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chino69
01-15-2008, 08:41 AM
Fellow shooters:
I've just purchased a Kreiger 6mm 1 in 7.5" twist LV #18 profile 30" barrel. I was going to have it chambered in .243AI, but after getting opinions from other shooters, I'm considering a 6 X 47 Lapua. I want to shoot everything from 95 grn. up to 115 grn. bullets at 500 meters +. This rig will be used for live varmints and maybe groundhog shoots. I would appreciate any info. shooters have around this cartridge. Specific questions:
1) What reamer maker should I use and what freebore would be right for the above bullet selections? What neck diameter?
2) Who's making dies and what is the best way to go? Wilson, Redding, etc?
3) What kind of velocities and accuracy are you guys getting with the heavier bullets?
4) Just run the brass through a full length die, prior to fireforming?

Any other info. would be greatly appreciated.
Chino69

tiny68
01-15-2008, 09:39 AM
Chino,

You've probably already this one. Here is an article from 6mmBR.com. http://www.6mmbr.com/gunweek073.html. It gives some reamer specs and turn versus no-turn neck sizes. You can use stock Redding 6.5x47 Lapua bushing dies and just reduce the bushing size to fit the 6. That is what Redding told me. I built a 6mm Rem AI last year. I think the 6-6.5x47 will be my next barrel.

tiny

chino69
01-15-2008, 12:45 PM
Chino,

You've probably already this one. Here is an article from 6mmBR.com. http://www.6mmbr.com/gunweek073.html. It gives some reamer specs and turn versus no-turn neck sizes. You can use stock Redding 6.5x47 Lapua bushing dies and just reduce the bushing size to fit the 6. That is what Redding told me. I built a 6mm Rem AI last year. I think the 6-6.5x47 will be my next barrel.

tiny

Tiny68,
Thanx. I read the thread several months ago and just re-read it. The 6 x 47 has many things to offer as does the 6.5 x 47. The problem, for me, with either of these choices is the additional cost of dies, brass, etc. I have a .243AI reamer, plenty of Lapua fireformed brass, custom dies, etc. If I had an unlimited budget, the 6 X 47 or the 6.5 X 47 would warrant serious consideration.
Chino69

mysticplayer
01-15-2008, 02:41 PM
As mentioned in your other post, my 6mm project rifle will use a 243AI reamer run short to headspace off 22/250 brass. After fireforming, you get a shorter 243AI or longer 6 Dasher.

I am using Win 22/250 brass as I see no benefit in the much more expensive Euro stuff. I would go with a slight neck turn to clean up.

you can still use your 243AI dies, just shortern appropriately.

My dies will be a shorterned Redding 243AI body die and a custom Lee collet die set for $55.

Performance will be identical to the 6XC and X47L.

Jerry

chino69
01-15-2008, 04:43 PM
As mentioned in your other post, my 6mm project rifle will use a 243AI reamer run short to headspace off 22/250 brass. After fireforming, you get a shorter 243AI or longer 6 Dasher.

I am using Win 22/250 brass as I see no benefit in the much more expensive Euro stuff. I would go with a slight neck turn to clean up.

you can still use your 243AI dies, just shortern appropriately.

My dies will be a shorterned Redding 243AI body die and a custom Lee collet die set for $55.

Performance will be identical to the 6XC and X47L.

Jerry

Jerry,
If you don't mind, tell me a little more about your set up using existing .243AI dies. I understand the part about shortening the dies but I don't understand the part about the .22-250 brass. Is the brass the same dimensions as the 6 X 47 brass? Would I just enlarge neck on the .22-250 brass to 6mm? If I can keep from investing in new dies and all the trimmings and use my current dies, this approach makes alot of sense.
Chino69

mysticplayer
01-15-2008, 05:18 PM
When the 22/250 brass is fireformed, it will have the same dimensions as the top 3/4 of a 243AI.

Set up the chamber headspace so that your 22/250 cases are a crush fit. That way you just fireform as the cases come out of the bag and save yourself a bunch of hassle and bullets.

To fireform, just use a small charge of pistol powder under some cream of wheat/cornmeal. The resulting case will have a shoulder that is almost fully formed. Body and neck ready to go.

I like to neck size using a Lee collet neck die (or your bushing die), trim, neck turn to clean up about 80% of the circumferance, deburr the flash hole and load'em up.

The first full pressure load will finish the forming process. That first firing is as accurate as the next so you can use it for plinking/hunting. Saves cost and barrel wear.

The dies are cut down to work off this case.... EASY.

Jerry

alinwa
01-15-2008, 08:21 PM
Jerry, please don't make statements like "Performance will be identical to the 6XC and X47L." until you've done it.

I HAVE done it and can tell you that neither the 22-250 case nor the .243 case will make enough pressure to be able to run with either the BR case or the 6.5X47Lapua case.

You're speculating and selling it as experience.


al

John Kielly
01-15-2008, 09:19 PM
A few guys in my neighbourhood have been chambering for 6 x 47 L by running a 6BR reamer in deeper.

How acceptable is that?

mysticplayer
01-15-2008, 11:04 PM
alinwa, I go by case capacity vs case capacity and both of these are near identical.

I also load to pressures that would not be considered proof loads.

If loaded to, dare I say it, sane pressures (no more then 65000psi or magnum pressures), their performance will be identical within the variations in barrels.

If your loads are no more then 65,000psi and velocity greatly exceeds those from similar volumed wildcat made from conventional designed case, then I will become a Lapua convert and never use anything else. I have used lapua brass by the way.

Yes, the Lapua 6.5X47L case is a brute. The case design is well engineered for some very toasty loads. That case is rated, by the factory, to work at 65,000psi (or near this) where other similar cases (22/250) are rated for less at least as defined by SAAMI loads.

We all know that a commercial case like a 308 or 22/250 or modern bottleneck whatever can all easily handle magnum pressures...SAFELY. That's primer pockets staying tight for at least 6 firings (mine are at or beyond 20 reloads and I use Win 308 brass).

The Lapua case, in BR quality actions, are allowing shooters to ramp up pressures to some interesting levels. Are those levels safe?

Put a strain guage on and let me know...

Jerry

PS from the last time I checked. A proof load for ANY modern rifle as defined by SAAMI is 80,000psi or thereabouts. I have proof load cases and there are no seriously flattened primers, leaks and it extracted for the action with little effort.

mysticplayer
01-15-2008, 11:36 PM
A few guys in my neighbourhood have been chambering for 6 x 47 L by running a 6BR reamer in deeper.

How acceptable is that?

Measure the reamer at the same length as the finished cartridge and see what the diameter is. Hopefully, it will be very close the diameter of your case in the web area.

If so, go for it. If much bigger then you will have to live with case bulge.

Jerry

alinwa
01-16-2008, 12:14 AM
Jerry,


your quote....."If loaded to, dare I say it, sane pressures (no more then 65000psi or magnum pressures), their performance will be identical within the variations in barrels."


I have no idea what you dare say nor what you consider to be sanity but this is a Bench Rest board and I answer as such. While someone like yourself may well be inclined to call a NASCAR racer "insane" even you must admit that he will NOT go out and win with some factory or "sane" motor.



If you want a round to be competitive then you MUST build it as such. The only way to do this is to design a round such that it'll take enough pressure SAFELY so as to be competitive. Neither the 22-250 case nor the .243/308 case fill this bill.


Now Jerry, you're welcome to your opinion that all BR competitors shooting the PPC and BR cases are "insane" but my guess is that Mr Kielly wants him some of this so-called insanity :D


John, running the 6BR reamer in deep is a splendid way to make a 6X47 IMO, and my opinion is pretty picky.


My way involves setting the shoulders back on 5 brand new 6.5X47 cases to use as your initial headspacing tools........you then chamber for crush-fit using a 6BR reamer, send some tightly fired cases around to folks for dies and real headspace gauges and saunter off into the sunset with all your ducks in a row or somesuch......


It's a good way.



al

henrya
01-16-2008, 12:15 AM
I just ordered my 6XC reamer. I've had just about every other mid size 6mm and this looks like the best yet. Great Norma brass, (I have some I formed to 6mm HLS and it is just lovely!). The brass is relatively cheap (55 cents) and its formed ready to load - no screwing around. And you just buy off the shelf dies from David Tubb.

The reamer for current Norma brass is known at Pacific Tool as revision C. This has Tubb's 3/4 degree and long freebore which is made to shoot the long bullets you are writing about. I ordered a 1 1/2 degree and .045 freebore for lighter bullets. I'd order the standard Tubb reamer for long bullets. If you have doubts about the throat Dave Kiff at Pacific can set you straight if you tell him what bullets you will shoot.

Now about this pressure thing. I don't see any big push to shoot those long pencil bullets loaded to the gills like some PPC shooters do with their little pills. What you do want is consistent velocity and consistent bullet performance to give consistent time of flight to long range. David Tubb has a new 111 gr. plastic pointed bullets he's shooting right now with excellent results. No meplat trimming with the plastic point. He's shooting 3050 f.p.s. with the 111 gr. and H4350 at comfortable pressure. There is no point in pushing your luck with marginal high pressure loads that kill your brass in a couple of firings.

alinwa
01-16-2008, 12:27 AM
Again, the 6.5X47 case will simply do things that Tubb's case cannot, safely.


And it is actually LESS hassle than using 6XC brass.


My definition of "good case life" is 50 firings.


al

John Kielly
01-16-2008, 01:43 AM
John, running the 6BR reamer in deep is a splendid way to make a 6X47 IMO
Thanks, al


and my opinion is pretty picky.
noticed & noted :rolleyes:

mysticplayer
01-16-2008, 12:50 PM
Jerry,
I have no idea what you dare say nor what you consider to be sanity but this is a Bench Rest board and I answer as such. While someone like yourself may well be inclined to call a NASCAR racer "insane" even you must admit that he will NOT go out and win with some factory or "sane" motor.

If you want a round to be competitive then you MUST build it as such. The only way to do this is to design a round such that it'll take enough pressure SAFELY so as to be competitive. Neither the 22-250 case nor the .243/308 case fill this bill.

Now Jerry, you're welcome to your opinion that all BR competitors shooting the PPC and BR cases are "insane" but my guess is that Mr Kielly wants him some of this so-called insanity
al

Interesting you bring up race cars as it is one of my other loves. I can say with certainty, that race cars are the safest vehicles on four wheels. The sanctioning bodies do everything in their power to ensure that the equipment lives up to the task while minimizing risks to the driver.

The sanctioning body rarely ever wants the cars to go slow!

The question above has little to do with pressure signs or stiff bolt lift - there will not be any. It has to do with chamber pressure and its relation to action/barrel - strength/fatigue/wear.

A very dangerous pressured load can still be operate with one finger lift on a BR quality action. It does not change the value of the pressure and its affect on the steel surrounding it.

Are the steels/materials used in BR actions that much stronger then commercial actions?

Is the fatigue life of the BR action substantially higher/longer then a commercial action?

These questions I have no idea on and have seen no info on the topic. Essentially in the BR world, it is a non issue.

That's DANGEROUS!!!!

IPSC has seen this problem after decades of high major load ratings. They saw how shooters would work all manner of engineering to meet that requirement and provide some shooting advantage. Absolutely cutting edge but riding the razors edge of disaster. After a number of guns failed, the rating have been lowered, guns no longer blow up, scores are still excellent and the top shooters still kick everyones butt.

We have not seen any mechanical failures in match rifles to this point (certainly none I have seen in the last 12yrs of shooting/wildcatting). Cartridge pressures continue to rise as shooters continue to push more velocity out of smaller cases. Tighter tolerances and stronger brass keep this trend going without pressures signs, but NOT WITHOUT ELEVATED PRESSURES.

SAAMI proof load pressures are there for a reason. They are not levels to be used on an ongoing basis due to the concern of increased material fatigue.

A cartridge fired at 80,000psi in a BR tight action WILL NOT SHOW ANY PRESSURE SIGNS but that much pressure does put strain on materials. Maybe these BR actions are that much stronger then conventional products? Maybe the actions are still too new to show the signs of fatigue?

Some feedback from custom BR action makers might be interesting. Wonder what they rate their actions for? Duty cycle at what operating pressures.

Yes, every action has a lifespan and will wear out.

Put a strain guage on these BR loads/rifles and see what pressure rating it gives you. If they are within the very safe magnum pressures levels of 65000, even a bit hot at 70,000psi, AWESOME. However, I suspect that shooters are treading much higher.

Safe???? I guess that depends on what you consider safe.

Personally, if I can't reach a velocity goal with a particular case at magnum pressures or a bit over, I simply go to the next larger case. Thus I have skipped over the 6BR and moved to a 22/250 variant.

YMMV.

Jerry

chino69
01-16-2008, 01:32 PM
A very dangerous pressured load can still be operate with one finger lift on a BR quality action. It does not change the value of the pressure and its affect on the steel surrounding it.

Are the steels/materials used in BR actions that much stronger then commercial actions?

Is the fatigue life of the BR action substantially higher/longer then a commercial action?

These questions I have no idea on and have seen no info on the topic. Essentially in the BR world, it is a non issue.

That's DANGEROUS!!!!

SAAMI proof load pressures are there for a reason. They are not levels to be used on an ongoing basis unless the desire for material fatigue is desired.

A cartridge fired at 80,000psi in a BR tight action WILL NOT SHOW ANY PRESSURE SIGNS but that much pressure does put strain on materials. Maybe these BR actions are that much stronger then conventional products? Maybe the actions are still too new to show the signs of fatigue?

Some feedback from custom BR action makers might be interesting. Wonder what they rate their actions for? Duty cycle at what operating pressures.

Yes, every action has a lifespan and will wear out.

Put a strain guage on these BR loads/rifles and see what pressure rating it gives you. If they are within the very safe magnum pressures levels of 65000, even a bit hot at 70,000psi, AWESOME. However, I suspect that shooters are treading much higher.

Safe???? I guess that depends on what you consider safe.

Personally, if I can't reach a velocity goal with a particular case at magnum pressures or a bit over, I simply go to the next larger case. Thus I have skipped over the 6BR and moved to a 22/250 variant.

YMMV.

Jerry

Jerry,
You bring up some very valid points that many never consider. A rifle chamber, for a split second, is a pressure chamber. Any pressure vessel or chamber expands, within the elastic range of the material, and returns to the former dimensions when the pressure goes away. Any material, particularly steel, is subjected to cyclical stresses. These stresses can be cumulative, and if the material is subjected to overpressure, the material can fail without warning. How do you know?

In the nuclear industry, we subject our vessels and critical equipment to non destructive examinations (NDE). This can be mag particle, liquid dye penetrant, eddy current, ultra sonic, or radiography depending on the material, stresses, and wear of the material being tested. Our steel also meets strict specifications followed by certified certificates of conformance that attest to the pedigree and certification testing of the material. Our continued operation depends on our ability to prove to ourselves and regulatory agencies, that our equipment is safe to run and perform it's intended function. This process also allows us to make accurate predictions with regards to when a component is likely to fail and implement the necessary precautions and preventive maintenance to preclude failure.

How does this tie in with shooting? Many shooters routinely run higher than normal pressures. Yes, custom actions are stronger and are made with better materials than factory. Most experienced shooters are knowledgeable enough to stay out of trouble. To make a long story even longer; impending failure may not be apparent to the naked eye. Just something to ponder.
Chino69

mysticplayer
01-16-2008, 01:48 PM
To make a long story even longer; impending failure may not be apparent to the naked eye. Just something to ponder.
Chino69

So how do we test our actions to ensure that all is well??

I have magnafluxed some WWI/WWII actions to look for cracks. Is that enough/the correct procedure?

I have also seen a dye product but have heard the magnets are better ? Any thoughts?

Do we just assume so many firings and the action gets parked?

I have heard that a life cycle of a bolt action is 100,000 firings (anecdotal). Does it drop off exponentially if fired at high pressures?

Any thoughts would be appreciated as we all want to have fun and be safe.

Jerry

chino69
01-16-2008, 02:53 PM
So how do we test our actions to ensure that all is well??
Any thoughts would be appreciated as we all want to have fun and be safe.

Jerry

Jerry,
The point I was trying to make is that if you stay with reasonable pressures and within the safety window (SAAMI specs.) that you'll probably never have to consider material failure as a result of fatigue. Those that push the envelope, are not really aware of what area they are operating in. The stress/strain curve shows the dimensional change in steel for a given amount of force. Within a certain range the steel will return to it's former dimension once the force is removed. Go beyond this point and you may have subjected the steel to internal stresses that will not be visible.

Liquid dye penetrant or mag. particle will migrate and identify an existing crack or cracks. Liquid dye penetrant takes more prep than mag. particle. Some of the more exotic testing is used for identifying bad welds, etc.

I'm not a metallurgist but have enough understanding of materials to know why specs. exist and how they were determined.

From an action standpoint, a magnaflux will show whether there are any surface cracks but will do nothing to show what is happening inside. Stay inside the safety zone and shoot without worry. If you do go beyond established safety standards, know what the hell you are doing and realize you are in a 'grey' zone.
Chino69

henrya
01-16-2008, 03:00 PM
"Personally, if I can't reach a velocity goal with a particular case at magnum pressures or a bit over, I simply go to the next larger case. Thus I have skipped over the 6BR and moved to a 22/250 variant."

I'm glad to read the last few posts. Its good to hear an intelligent discussion of pressure and safety. I find nothing macho about wrecking an action for a few feet per seconds velocity. But at times that what seems to motivate the "load it 'til it nearly pops" crowd.

alinwa
01-16-2008, 03:14 PM
Jerry, good point about the race cars being SAFE.

To answer your question in real-world terms.............to the best of my knowledge NO ONE has EVER blown up an action used for Benchrest shooting except by using the wrong powder or something. These actions have redundancy built into them.


Now on the subject of BR chamberings in factory actions...........again NONE have ever been blown as far as I know. The actions will tell you when they're being over-stressed. The symptom is hard bolt lift coupled with sticky extraction. The cause is action flexure, the chamber/action ring, lugs expand just a little further than they should and when they collapse back they trap the case. On this note, these signs show up long before catastrophic failure is imminent. It would take a lot of work to flex an action long enough or cycle it enough times for it to show signs of fatigue.



I do NOT advocate anything but Rem 700 or Savage "110" series factory actions for building for pressure. I also note that factory actions WILL often get sticky before a custom will. If you search my posts you'll find me to be one of those who DOES NOT advocate the use of factory actions for magnum builds. My 300WSM project uses a BAT with the large threaded tenon JUST for this reason.


A properly modified 700 or Sav will allow you to run pressure/velocity up SAFELY using Lapua small flashhole brass, pressure that will destroy any other case like the 22-250 or .308-based variants.


If your method worked then you would see folks running other cases for BR accuracy, it doesn't. I happen to be one of those who've spent the money to prove this to my satisfaction. I've had dozens of barrels/chambers cut to "BR Spec" using full-on BR platforms and shot them extensively head-to-head with BR stuff.


Henrya makes a point about 1000yd stuff not needing to be run at the higher pressures...........While this has been true, 1000yd shooting is evolving rapidly. What was considered to be cutting edge accuracy as little as 6-8yrs ago wouldn't even make a showing today. High pressure and FB bullets are making inroads. Current accuracy levels for VLD's is "in the 2's" at 100yds.......G D Tubb's stuff doesn't meet this accuracy standard, it's used for a different game requiring less in the way of inherent accuracy and more about function from a mag.


Your points about building IPSC and race pistols is well taken, here we agree, BUT, I see no valid comparison between a racegun and a BR rifle.


I've blown up enough bolt action rifles to have some basis for comparison........believe me, when a bolt action lets go it's as if the brass case didn't even exist. IMO using yield strength of brass as a baseline against which to gauge load pressure is perfectly safe, a valid way to measure safety parameters.


Now the DAY someone pops an action open from pressure while working under the yield strength of the brass will be the day that I change my methods!!!


Meantime, Lapua BR, PPC and 6.5X47 cases will SAFELY do things that no other easily available line of cases will do.


Just try them.............make up an un-modified 6.5X47 barrel for your platform and see if it doesn't eat your mystic up, with less powder and commensurately longer barrel life. I've just taken the time to completely scrap my 10yr-long .308HBR project (based on modified .308 Lapua brass) and am changing it all over to 30X47 at great expense. The new brass opens a door which didn't even exist 5yrs ago, it's revolutionary.


quote - "Yes, every action has a lifespan and will wear out."


Don't know that I can agree with this..........there are BR actions out there with hundreds of thousands of cycles on them that are still capable of winning, safely.


IPSC guns wear out, shottyguns wear out. BR actions? Not really, and if they do, guys just bore them out BIGGER (less strength?) and bush or replace the bolts to tighten them back up.




al

mysticplayer
01-16-2008, 03:16 PM
Chino69, I guess I was putting false trust into the action testing. Wasn't telling me buggerall:eek: Thanks for your insights.

The way it was explained to me was imagine bending a paper clip back and forth. For a while, it keeps bending but eventually it stops bending and breaks. The less you bend it (lower deflection), the longer it takes to break (if ever).

Bend it too far or too fast and it will break sooner or right away.

Once steel gets 'stretched' it changes it's properties in unpredictable ways and is not reversable. You got a time bomb.

Not something I ever want to find out about....

Jerry

chino69
01-16-2008, 03:32 PM
Chino69, I guess I was putting false trust into the action testing. Wasn't telling me buggerall:eek: Thanks for your insights.

The way it was explained to me was imagine bending a paper clip back and forth. For a while, it keeps bending but eventually it stops bending and breaks. The less you bend it (lower deflection), the longer it takes to break (if ever).

Bend it too far or too fast and it will break sooner or right away.

Once steel gets 'stretched' it changes it's properties in unpredictable ways and is not reversable. You got a time bomb.

Not something I ever want to find out about....

Jerry

Jerry,
Your paper clip analogy is as deep as you need to go because you understand the concept perfectly.
Chino69

mysticplayer
01-16-2008, 05:34 PM
al, you are right, Brass will fail before the steel action. however, repeated beatings on said action can lead to a structural failure with less load then expected. It's called metal fatigue.

Same idea as commuter jets blowing their tops. Too many compression cycles.

It's back to proof loads. One bang and nothing blows up. Keep banging away and ???????

You are absolutely right that the new 6.5X47L is the super case. it will survive where other cases fail. 110% in agreement.

The issue I have is that conventional brass like Winchester, has no issue surviving continuous beatings at magnum pressures. Magnum pressures is the top that I feel we should be playing at (max 70,000psi).

if you are loading to levels where a conventional case is loosing primers in only a few firings. You have EXCEEDED the yield strength of brass and I bet that pressure level/elastic limit is well above 70,000psi. Did a quick search but couldn't find the chart I saw before.

I am suspecting that is around 90,000 to 95,000psi. From memory, a commercial action is approaching destructive pressures around 110 to 120,000psi. That's getting really close to 'stretching' stuff in ways not friendly to longevity....nor good health.

Using a brass that has a special alloy with a much higher elastic limit simply allows you to start approaching the limits of the action/barrel.

I am sure that modern BR type actions are built very strong. Maybe they have a life cycle much longer and stronger then a conventional action???? Without knowing what that is, we are only ASSUMING that these actions are stronger or when they will fail.

Steel is steel and there are limits no matter how lofty they may be.

Continuous shooting at proof load pressures, or higher, may be fine for a whole bunch of BR actions but it only takes one failure to ruin your day.

For me, it is simply not worth the risks.

Jerry

alinwa
01-16-2008, 06:02 PM
Ok,


First of all, the paper clip analogy is hopelessly flawed. It has no relevance.


"Bending a paper clip" means bending it beyond it's ability to spring back. In other words BENDING it, not just deflecting it like a spring. If EVER an action is "bent" then it may be considered to be irreparably ruined, destroyed. Now if you just set and fiddle with the paper clip, if you pinch it between thumb and forefinger and LICK it, you've bent it about as much as an action is bent when you fire it. You could lick a paper clip for a loooong time before it failed due to fatigue. (No jokes or brags please :D )


FahGIDDA'bout paper clips, think springs..............the springs on your automobile survive millions of cycles, tens of millions if like me you live on the end of a mile of dirt road.


Factory actions FLEX, like springs, they don't "bend". Every time you drive over a bridge, every time you go into the mall, every time you walk on a floor or slam a door or lean against a wall you're deflecting or flexing the structure. The key is that you don't flex it enough to cause permanent damage. There are SOME isolated instances which the shooting/building trades are well aware of where bolt actions of certain heritage are considered "weak".............these actions shouldn't be used, period.


What I'm saying is that IMO you can fire loads exhibiting pressures BELOW THE YIELD POINT OF THE CARTRIDGE BRASS in a 700 or a Sav or a modern custom action............you can fire a million rounds and not find any permanent or cumulative damage. No stress cracks. No crystallization. No deformation. No displacement or molecular rearrangement of any sort, just plain old abrasion wear which must me controlled through cleanliness and proper lubrication.


Firing a rifle is kinda' like smacking an anvil with a hammer, only with something softer and more yielding in between to protect the anvil............gener'ly the anvil just shrugs it off. Consider the cartridge case to be your finger between the hammer and the anvil, your finger will "fail" long before you damage the anvil.


Again, I stand to be corrected.........I'm the Original Safety Geek, search "safety geek" and my name will pop up. If someone shows me so much as ONE example, ONE shred of evidence to the contrary, I'll rethink my viewpoint.


Meantime I'm very comfortable using cartridge brass as my "CUP method" of ascertaining safe working pressure.



al

mysticplayer
01-16-2008, 07:11 PM
Here is a link to Olin Brass for an analysis of the characteristics of the brass they use in cartridges.

Brass type is #260 Yield Strength for various levels of hardness:

Annealed 45 to 61000psi - necks which makes sense
3/4 Hard 64 to 74000psi - guessing this is in the case web area
hard 71 to 81,000psi - guessing this is the case head/primer pocket area

http://www.olinbrass.com/pdf/alloyguide03.pdf

Not sure where Lapua fits in this but if it tolerates pressures above 81,000psi without yielding, that's getting pretty stressful on the action.

YMMV

Jerry

PS the cartridge doesn't not insulate the chamber/action from the pressure at all. The cartridge expands to fill the chamber and becomes a non compressible solid allowing all residual pressure to be applied on the barrel and action.

The cartridge may cry 'ouch' but it will not stop the forces from acting on the steel.

Long term hammering on an anvil will destroy it even though each impact is not enough to destroy it. Surface work hardening leading to brittleness. Why old anvils aren't so popular with metal workers.

keithcatfish
01-16-2008, 09:27 PM
What metallurgcal differences (as compared to lesser brass) are unique to Lapua brass that enable it to tolerate such higher pressures?

henrya
01-17-2008, 12:53 AM
And what is so special about Russian and BR and 6.5X47 Lapua that makes it indestructible? How about Lapua .243 or 6.5X55? Lapua 30-06 or .308 -- is it in the same league?

Its all good stuff but is it really magic?

henrya
01-17-2008, 12:56 AM
snipped:

I've blown up enough bolt action rifles to have some basis for comparison........believe me, when a bolt action lets go it's as if the brass case didn't even exist. IMO using yield strength of brass as a baseline against which to gauge load pressure is perfectly safe, a valid way to measure safety parameters.

al


You're scaring me now.

alinwa
01-17-2008, 03:15 AM
Ok,


Regarding the relative "hardness" of Lapua brass, I know nothing of brass composition, only how it acts.

You can get .243/308 brass or 22-250 brass from a variety of mfgrs, Rem, Win, Fed, Lapua, Norma, Hornady etc........of all the available brass, Lapua will give you the highest velocity AND good caselife. Winchester runs a close second with all others lagging at least 100fps behind.

For immediate comparison let's just stick with Norma and Lapua since they're manufactured to similar standards of uniformity. Anyone who's taken the time to use them both has found that if you work up a stiff load in Lapua brass and then try to achieve the same velocity/pressure using Norma you're doomed to fail. Same rifle, same everything and you simply cannot get the same performance out of Norma brass. Same with 6BR, Norma makes gorgeous 6BR brass, NOBODY uses it. Why? because you CANNOT compete using Norma brass. Norma brass fails before a usable competitive pressure is achieved. Sure matches have been won with Norma brass.........Matches have been won with Win or any other brass you'd care to name but for pure-dee Benchrest accuracy you will be hard-pressed to find ONE entrant in a field of thousands that isn't Lapua. The only people not using Lapua are those who don't know any better, or who've chosen a design-path which precludes Lapua or those who're still trying to prove something. Or those precious few who've run into a windfall of "something else" and are willing to risk thousands of dollars on the brass they've got. Some like GD Tubb simply took the bull by the horns and MADE something from thin air........in Tubb's case he spent the time and money to develop a case specifically to address these issues, a case which was then eclipsed by the 6.5X47 case, bad timing.


Lapua makes the toughest brass available, by a wide margin. There are some other exotic European contenders but for currently available and easily obtainable brass Lapua rules the roost. This isn't some "perception" it's simply fact.


BUT.........this isn't ALL of the story.


I realize that this is the factory/hybrid board but it's STILL Bench Rest Central not Grunting Around The Communal Rock Central so my view will be from the standpoint of Extreme Accuracy.


A group of us extremists have been looking for a better 22-250/.308 case for literally years.............12 yrs in my case. You see, for a case to REALLY make pressure it must not only be HARD but it must have a small primer and flashhole.....I've got boxes of URBR brass, the ORIGINAL Bench Rest case......useless junk. I called Kaltron-Pettibone several times over a 5yr period begging them to get Lapua make a run of small-primer .308 or 22-250 brass, preferably with undrilled flashholes. I stayed in contact with GD Tubb from day one with his 6XC case. I got samples and feedback on all of the three runs of brass, all three "generations" so to speak. No dice. I completely shelved my 6MM longrange projects and developed a 30HBR case from Lapua .308 brass which looks pretty weird but shoots well.............but it will NOT make good pressure. About 3250 W/112-118's tops.......


And THEN!!!! HHOOOWWAAUUGGHHHhhhhhhhhHHH!!!! Lapua came out with a BRAND NEW case, the 6.5X47. They did EVERYTHING right on it!.


This new case is the BEANS!


It is the ultimate 22-250/308 size case. AND lapua brought it out in a good necksize at 6.5. I doubt that I'll ever shoot it in 6.5 but that's not the point.


The point is that it's ULTIMATE BRASS.........it's a case from which to build wonderful things. It's what the URBR case SHOULD have been.



To illustrate;

The 6PPC simply IS the Benchrest round of choice for a variety of reasons, IMO the single BIGGEST REASON is that no one makes good factory available 6PPC cases. And every time someone DOES make one the BR community spurns it...........it gets tried, it doesn't agg, it goes away. The REAL reason that the 6PPC is such a world-beater is that making GOOD brass is required. You will not win unless you make your brass, or have it made, from .220 Russian cases. It's that simple. Most folks don't know why.


MAKING brass either in 6X47 or 30X47 from the new Lapua case offers the exact same advantages.............it gives one opportunity to make cases which will agg. It forces people to actually fit their brass to their rifle which is key to accuracy.



Given an accurate platform it's dead easy to test all of this, it just takes time. All you have to do is make brass from several different makers and by several different methods.......


Some loads will be fireformed with some slop, like .002-.005 like any "normal" chamber.

Some will be fireformed with slop but you will "seat the bullets long".

Some brass will be fireformed with grease on them so that they "slide back in the chamber".

Some loads will be tried each way and for each brand of brass.

And SOME loads will be set up to jam against the shoulder for fireforming.

Different methods, different brands of brass.

When the testing is done and the dust settles it will be found that yes! Properly fireformed brass will absolutely agg better than improperly fireformed stuff and YES! Lapua brass is magic! :)


To answer your specific question Henrya, YES Lapua brass will out-perform the others regardless of conditions........but more telling, ONLY Lapua brass will give you that winning edge.



I've spent some time and money testing this.



I've got 5 different 6BR chambers, no not 5 chambers from the same reamer but 5 different reamers. I've also got 5 different 6BR barrels cut with the SAME reamer but all with slightly different headspace. I've got barrels which have been re-chambered 3 times...........same barrel, same rifle, three chambers. And I've spent endless hours actually shooting this stuff head-to-head. I went so far as to order 2 Krieger 6MM barrels from the same production run, tapered the same, identical as they could be. I chambered one in 6BR and one in 6PPC just to see if I could see the difference between a "production cartridge" and the 6PPC. My original intent was to agg them and then switch them around........swap chambers. I never finished the test. I didn't finish the test because I learned what I wanted to know, I'd been chasing the wrong thing. I now apply Benchrest Technique (6PPC brass forming technique) to a wide variety of cases. They SHOOT!


Even the .243AI will shoot pretty good for a round or two but then, just as you've formed a good case you run into problems maintaining it.........the long 40* shoulder doesn't respond well to FL sizing.


FIRST one must fireform a case to perfect fit, THEN one must devise a way to MAINTAIN that perfect fit.


Much easier said than done.


But when it's done it's a marvelous thing. A perfect case will last literally forever. I've fired 6BR cases until the flashholes were burnt out into weird shapes and the necks were wearing thin from abrasion. IMO a case doesn't even start to shoot right until it's been "seasoned" by about three firings.


But hey........these last are just MY OPINIONS.

The part about the Lapua brass being more durable is FACT.

The part about the 6BR/PPC cases with their small flashholes and small primer pockets performing 'WAYYY beyond their size is FACT.

The part about the new 6.5X47 case being a world-beater is IMO FACT!! :D:D:D


LOL


Time will tell, it's still in its infancy.





Ohhh, yeahh and Henrya, that part about blowing up actions :) I was in gunsmithing school when I met a gentleman who was really interested in the 6.5 Arisaka's. Julian hatcher or PO Ackley or one of those Giants had made the statement that two of the strongest bolt actions on the planet were the much maligned Krag-Jorgensen and the Arisaka. This fellow proceeded to blow some stuff up! I thought at the time that it was insane. I then met another guy who'd done the same thing.............then I ended up building a rifle on a Rock Island Arsenal Springfield by accident........and then I got wind of a couple of actions that had been destroyed cosmetically........and then I got curious about just how much pressure WAS built into a small ring action that had been chambered to a magnum.......and then I got ahold of some actions that had been through a fire........one thing led to another and I've been around some pressure and destruction.


Right now I've got a sporterized Springfield 30-06 in one of my vises just waiting to be blown apart...........problem is, I've been instructed to blow it up in such a way that I can use it as a demonstration piece in our Hunter Safety class...... Really, a fellow donated it to the class and has asked me to show what a blown up action looks like. It's got a bulged barrel from some earlier mishap and instead of re barreling it he's asked me to blow it apart. We've got broken shotguns and pistols, we've got the pictures of the defective Sako's that are floating around. We've even got access to one of them, one with the classic curled out fluted pattern barrel rupture. We've got examples of magazine detonations and loaded guns that have been through fires.....but real honest-to-goodness pressure failures of bolt-actioned rifles are few and far between.



I've learned one thing from being around (controlled) action failures........it takes one hellacious amount of pressure and only one out of twenty actually LOOKS impressive. I'm stymied as to exactly HOW to get this one to where I want it. I want it ruptured, most of them just crack and bulge. I'm probably going to drive a bullet about 3" down the bore and then fire another one onto it using Bullseye........this will all happen down on the HE testing range under an explosive mat of course.


See, the thing is, speculation on "safety" just isn't in me.........The Good Lord only gifted me with two eyes and ears and at 45yrs I've still got perfect hearing and 20-20 vision..........I don't MESS with that! I wear sunglasses and earmuffs while I mow my lawn. My dad thinks I'm crazy but then he don't hear so well :)


I DO NOT take the prospect of action failure or brass failure lightly.


I believe that Lapua brass will allow you to SAFELY go where you will not go with another brand..............just like race cars are built safe, so are BR chamberings, done right.



Whewww my fingers are sore :eek: All that and the steenking post is so long nobody will prolly even GET this far......:rolleyes:


Ohh well, I mean well.


LOL



al

henrya
01-17-2008, 10:23 AM
Al, You're pretty entertaining but I'm pretty hard to convince. And I give you high marks for consistency of your viewpoint - it doesn't change. But saying it over and over again does not make it right.

I don't see that the only way to get accuracy is to "make pressure". I don't see that in what the competition people here report. The other thing I don't see is the quoting of pressure figures as if you have a strain gage built in your trigger finger. The pressure numbers getting bounced around here are pure speculation about something that simply is not to be guessed at.

I've been around and seen blown up guns too. I consider my experience there to be mere conjecture just like yours.

I give now - you've worn me out.

Best,

vlcakc
01-17-2008, 01:56 PM
I have absolutely no issue with Al's statements about Lapua brass being the toughest and best commonly available to reloaders. As reloaders we control the working pressures of our ammo. What does the manufacturer recommend in the way of pressures? The preface to the Lapua load data states that pressures are limited to the lesser of CIP/SAAMI specs. The Lapua.com website doesn't currently list the 6X47 L in their load tables, but does list the 6BR Norma. The max loads shown are quite a lot lower than many BR shooters routinely use. Why? I don't know, probably to placate the lawyers. However, since I'm rather attached to my fingers and eyesight, I'll stick to the manufacturers recommendations. Vic

alinwa
01-17-2008, 11:09 PM
Henry,


I don't have to convince you...........just go to a BR match and see for yourself.


Even the 1K crowd is coming around. High pressure = consistency.


al

chino69
01-18-2008, 07:27 AM
The max loads shown are quite a lot lower than many BR shooters routinely use. Why? I don't know, probably to placate the lawyers. However, since I'm rather attached to my fingers and eyesight, I'll stick to the manufacturers recommendations. Vic

The reasons the max loads are lower than most BR shooters routinely use are, as you pointed out, lawyers as well as a safety factor. A safety factor takes into consideration the premise that people will make mistakes, differences in brass, chambers, powder lots, etc. The max loads are lower so that this safety factor is built in and on the conservative side. A beginner is best to adhere to the published loads until they firmly have their feet on the ground, have experience and knowledge and the confidence in their skills before they venture out of the safety zone.
Chino69

flatlander
01-18-2008, 11:02 AM
I recently finished building my 2nd 6x47L - this one on a BAT 3L. The one issue I have with this case is that - at least in colder temps (28F-45F) - it's not unusual to get fairly high ES & SD numbers relative to what I typically see out of my Dashers (have four of them, and use nothing but Lapua cases in all). I saw the same thing with my 1st 6x47, which I built on a SA 700, and which, coincidentally, was also finished just in time to break in the barrel and do initial testing in cold temps. I've used Fed 205Ms, CCI BR4s & 450s, R 7-1/2s, and even old nickel-plated WSRs, and all gave velocity spreads of 30-50fps with slow powders typically used (N160 is my favorite) with 105-115gr. bullets for LR prone shooting. Let the temperatures warm up into the 50-60F range, and things begin to improve.

At this point, I'm not sure whether it's the small primer or .060" flashhole, or the combination. However, when David Tubb wrote the specs for his custom made 6XC brass, he went with a large primer when it would've been just as easy for him to specify a small primer pocket. Granted, most of us won't be shooting BR or LR prone in sub-freezing temps, but it's still something worth mentioning. I'm not complaining about the 600yd. accuracy I'm getting out of the BAT with its 7.5-twist Krieger & DTAC 115s, but I'm somewhat concerned about the ES when we move back to 1000.

alinwa
01-18-2008, 12:45 PM
Flatlander,


So how do you make your "DAsher" brass to avoid the "problem" of small primer and flashhole?


al

mysticplayer
01-18-2008, 02:14 PM
I recently finished building my 2nd 6x47L - this one on a BAT 3L. The one issue I have with this case is that - at least in colder temps (28F-45F) - it's not unusual to get fairly high ES & SD numbers relative to what I typically see out of my Dashers (have four of them, and use nothing but Lapua cases in all). I saw the same thing with my 1st 6x47, which I built on a SA 700, and which, coincidentally, was also finished just in time to break in the barrel and do initial testing in cold temps. I've used Fed 205Ms, CCI BR4s & 450s, R 7-1/2s, and even old nickel-plated WSRs, and all gave velocity spreads of 30-50fps with slow powders typically used (N160 is my favorite) with 105-115gr. bullets for LR prone shooting. Let the temperatures warm up into the 50-60F range, and things begin to improve.

At this point, I'm not sure whether it's the small primer or .060" flashhole, or the combination. However, when David Tubb wrote the specs for his custom made 6XC brass, he went with a large primer when it would've been just as easy for him to specify a small primer pocket. Granted, most of us won't be shooting BR or LR prone in sub-freezing temps, but it's still something worth mentioning. I'm not complaining about the 600yd. accuracy I'm getting out of the BAT with its 7.5-twist Krieger & DTAC 115s, but I'm somewhat concerned about the ES when we move back to 1000.

It's the small primer and how much flash they have. Been working with a 223 and even with so much less powder, I had to switch from a BR4 to a 450 for cold weather shooting (right around to below freezing). Stringing and flyers with the BR4 in the cold were very obvious.

Had the same issue with a 6BR. The BR4 is just fine in the warmer temps.

I do compete in the cold so having reliable ignition in the cold is very important to me. That is why my next 6mm will have a LR primer. I can tailor from a very soft BR2 to a 210M or even a 215M mag primer depending on the temp. I will always have enough brisance for ignition.

The use of a small rifle primer is really to help with limiting pressure signs like cratering and flattening. Will show up much sooner using a LR primer. However, that level is still at or over 70,000psi so we are already in the toasty range.

I know, I know, there is 'lots of evidence that small primers are more accurate'. Will I have seen lots of very accurate LR primer cases too.

Many modern powders burn their best at magnum pressures. I have tested lots of the Hodgdon Extreme line and ALL have burnt cleaner with less velocity variations when pressures reached magnum levels. Accuracy tailed off quickly beyond that though.

I have never seen any testing to show a duty cycle for a commercial/custom action at/near/over proof load pressures (80 to 85000psi). We know that at magnum pressures, the actions pretty much live forever. We know that metal fatigue grows exponentially with pressure. We just don't know to what extent (if some engineer has that data, please post).

The trend is for higher and higher pressures because the actions are built to such low tolerances. There are simply no warning signs. As I have said before, that is leading us down a very dangerous path.

I bet alot of shooters would back off their loads/change cartridges if they found out what pressures they were running.

Until there is a body of proper testing to show we can do it, I lean towards safety and will burn a few more grains of powder in a slightly larger case to reach the same velocity. Barrel wear will be no different and arguably better then a small case run at 125%.

Jerry

flatlander
01-19-2008, 01:22 AM
I've never had a problem with ES/SD in the Dasher - cold weather or hot -which is the point of my post. It looks to me as though the 6x47L's extra case capacity relative to the BR or Dasher is the reason for the higher ES/SD numbers. What else could it be? As has been pointed out, the 6x47 is just a longer 6BR - nothing else is changed. The only way to take advantage of the extra case capacity without running excessive pressure is to fill it with slower powders than we use in the BR & Dasher cases. The slower the burn rate, the heavier the deterrent coating. The heavier the coating, the more effect the primer is going to have on consistent ignition.

I'm not about to give up on my 6x47s, and in fact am really looking forward to shooting the new BAT at 1000 out at Byers. I just felt the experience I've had in colder temps was worth mentioning.

alinwa
01-19-2008, 02:39 AM
Dennis that makes perfect sense......I'm still in the process of just getting the basic 6X47 up and running and I expect that within a short time folks will be pushing the shoulders back for exactly the reason you've stated........but that isn't a bad thing, at least with the new case one has the neck to work with and it's dead easy to SHORTEN cases :)


Keep us posted please, I'm sucking up any and all info on this new case.


Thank you.


al

mysticplayer
01-20-2008, 01:03 PM
As has been pointed out, the 6x47 is just a longer 6BR - nothing else is changed. The only way to take advantage of the extra case capacity without running excessive pressure is to fill it with slower powders than we use in the BR & Dasher cases. The slower the burn rate, the heavier the deterrent coating. The heavier the coating, the more effect the primer is going to have on consistent ignition.

YEP, why my wildcat will use a LR primer. ZERO chance of an ignition problem.

Jerry

chino69
01-23-2008, 10:22 AM
Anyone have experience enough to comment on the 6 X 47 Lapua vs. the
6.5 X 47 Lapua? I've read about the differences but would like to hear from those who can tell me if one is better than the other. What I'm looking for is performance at 600 meters, load info., bullet selection, etc. I'm trying to make a decision to go with one over the other. Any experience would be appreciated.
Thanx in advance,
Chino69

mysticplayer
01-23-2008, 10:54 AM
chino69, 6mmbr.com gun of the weeks. Recent rifles with a comparison of both of these wildcats.

My take on LR competition (F class) is always to reduce wind drift as much as possible with the lowest level of heat and recoil.

The 6.5 X47 is a very accurate cartridge for the 123gr bullets. Not big enough capacity for the 139/142gr bullets in my opinion.

6X47L is similar in case capacity to the 6XC/similar wildcats. Works really well with 105/115/117gr bullets. I feel this case volume is ideal for the heavy 6mm bullets.

Between the two, the 6X47 is best for its cal so would give better LR performance. The 6.5X47 is a bit small as a 6.5.

Now if you compared the 6X47L vs the 260AI, that would be interesting.

All are equally accurate....
Jerry

alinwa
01-23-2008, 01:17 PM
Jerry, again......


"All are equally accurate...."


I realize that you believe this but please don't spout it as fact. I've spent many thousands of dollars trying to prove that "inherent accuracy" is a fallacy. MANY chamberings and MANY barrels/rifles...................And I was WRONG!


"Inherent accuracy" is NOT a myth. And once one understands the parameters it's easy to see why.


Getting your information from "Quickload" or whatever does NOT address accuracy.



al

mysticplayer
01-23-2008, 07:33 PM
alinwa, my thousands of dollars and 12 years of real world testing and wildcatting teaches me a different set of conclusions.

Don't assume my results come from a keyboard or computer simulations. They most certainly don't!

So let's not assume my info/results is less valid then yours. You post what you feel is right. I will post what I feel is right. Our views may differ...it's all good.

For your information, never used Quickload.

And YES, I do stand by my statement based on my experiences that the discussed cartridges are EQUALLY accurate or can be made so.

Ideal cartridges/combinations for a particular task/sport not withstanding.

Jerry

alinwa
01-23-2008, 09:05 PM
So Jerry,


You've actually USED the 6.5X47 case and the 6BR case and the .220Russian case before??? And you've found them to be "equally accurate" to things like .260's and .308's and .243's and 6XC's and 22-250's?

In your EXPERIENCE a 6.5X47 is "equally accurate" to say a 6.5X.284?

Or a 6XC is "equally accurate" to a 6X47 or a 6BR or a DAsher?


If so, then I stand humbly corrected...................


Ohh, and BTW, it's not "all good". By your reasoning some poor fellow could be led to spend his hard-earned dollar on a .243 or a .260Rem instead of a 6X47 or a 6BR or a 6PPC because "that way he's be more versatile" and "they're all equally accurate anyway".............or are you somehow separating the 6.5X47 case from the Benchrest brass mix, from experience? Or have you "experienced" benchrest accuracy with some of your previously mentoned chamberings?


Or are you now flat stating that your "Mystic" cartridge is as inherently accurate as say a 6BR?


al

mysticplayer
01-23-2008, 10:19 PM
alinwa, I sense that no matter what I state, you will not believe me so I will only say this.

I have wildcatted many cartridges in many cals. I have built over 28 rifles using a variety of components. All to test various theories and ideas. I have shot thousands of rds of ammo at various distances as far as 1800m (1950yds). I use this experience to make my statements.

You believe what you want to believe of my experiences. I certainly don't have the interest to question yours.

You can also refer to those more worthy then I. If you do a bit of snooping, there has been lots of experimentation in various chamber styles and shapes and cals. Their results mimic mine. Maybe we all did it wrong.

I bet the next post you want is for me to post all these names, all the references, post all the data. Again, you don't believe me so that's fine.

As for my 6.5 mystic, it shoots well. How well? As I have written for 6mmBR.com Gun of the Week #75 - barrel one shoots in the 1's and 2's at 200yds with the occasional group in the 0's. Barrel two shoots more in the 2's with a few in the 3's and occasionally in the 1's.

Same everything except the barrel. Is that accurate enough to equal other cartrides and cals?

Which is more important - cartridge or barrel?

If you looked at 20 6PPC BR rifles, do they all shoot equally well? I bet they don't but there is a desired level of acceptable performance. Some just lean more to the low end of the scale.

With todays understanding of chamber design and powders, a 6BR through to a 243 can be equally accurate. It has already been proven by others much more experienced then I.

As I remember the experiment, a known gunsmith took a quality BR grade barrel/rifle and started with a 6BR. Shot it for average group then continued to run the reamer in deeper till he reached the 243 length. The accuracy level didn't change but the velocity sure did. Was this one experiment a fluke, a hoax?

YMMV, 'nuff said.

Jerry

alinwa
01-23-2008, 11:03 PM
Yup, that's what I THOUGHT you were saying :)


Thank you for a clear confirmation.


al