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skeetlee
08-01-2010, 02:59 PM
Fellas i have been shooting my BAT 3 lug Robertson's stock Krieger 18 twist 30 br the last couple days and im a bit discouraged. .3's is about as good as i can muster at this time. Im seeing a bullets worth of vertical in just about every group. I am using 4198 and i have went from 32.5gr all the way up through 34.8gr using 118 and 112 bibs. I have tried 3 different seating depths but it doesnt seem to change much. I have seated at full jam 10 off full jam and 20 off full jam, even a group at 28 off full jam. ( I call jam the max length before bullet to lands push back) Im trying not to do to much at once. I started going through the powder charges with the same seating depth. then i change seating depth and go again. The rifle will put a few bullets into the same hole on occasion but the final result is a bullet of vertical not much more. Its not real bad but i think this rifle should shoot low .2's rather than mid .3's. the winds were a little tricky but manageable. Not real sure what to try next. maybe a different powder? Im using lot 4757 of 4198.
Today was a bit better as i increased the powder charge to 34.8 after seeing so much vertical yesterday. So far the best i can tell from the two days of shooting is that the rifle shooters better with the 34.8 and the 118 bullet back about 25 off full jam. Do you think the bullet is still in the lands at 25 back?
I know its hard to suggest anything by all this, i just thought it might make good conversation. Ill get it figured out!! I did shoot a 1 and a low 2 today so it is looking up, i just wish i could get the vertical out. You know and maybe its that the 30cal bullets make the groups look like there's more vertical than there really is?? All in all i think a low .2 agg is reasonable, but im not there yet. Thanks fellas!! Lee

abintx
08-01-2010, 06:12 PM
Im seeing a bullets worth of vertical in just about every group. I am using 4198 and I have went from 32.5gr all the way up through 34.8gr using 118 and 112 bibs. I have tried 3 different seating depths but it doesn't seem to change much. I'm trying not to do to much at once. I started going through the powder charges with the same seating depth. Then I change seating depth and go again. The rifle will put a few bullets into the same hole on occasion but the final result is a bullet of vertical not much more.

Not real sure what to try next. Lee

You didn't say anything about which BUSHING you were using for NECK TENSION.

Are you using a .326, 325, .324, or a .323? I suggest trying the .325 and the .324. [The 30BR likes a lot of neck tension.]

When I was getting small cloverleafs with the .325, Randy Robinett suggested I try the .324. When I did, everything tightened up real nice. :)

nhkuehl
08-01-2010, 06:30 PM
I don't know if you're shooting off a bipod or rest or free recoil, etc. but it may not be your load* but shoulder pressure or a too hard front bag (something mechanical).
*What is the extreme spread in fps of your loads? If you don't have pressure yet try going up a little more, since you said your last increase was an improvement. You should go from vertical to horizontal when you pass the node. Just thoughts. - nhk

daz
08-01-2010, 06:40 PM
X 2 re: neck tension. Mine always liked a lot of jam and a case full of N130 or Re7 with a .325 bush but REALLY started to work when i went to a .324 bushing. Hard to believe that such a small change would have such an obvious effect, but it did.

Darren

jackie schmidt
08-01-2010, 08:36 PM
I guess neck tension preference is something that varies among shooters. With my 30BR, (you know how it shoots), I use a rather light neck tension. Actually, it amounts to just a tad over .001.The bullets are probably .005 into the lands. The die has no bushing, measures about .326.

I have no idea why I get away with such a light neck tension, both the 17 and 18 twist barrels shoot equally well in the Rifle.

One thing you might check is the firing pin spring fall. Action builders seem to like a light spring, mainly so the actions will open with just a fip of the finger, and everybody will marvel at the smoothness. But, that is a source of erractic ignition, I would use no less than 22 pounds............jackie

tenring
08-01-2010, 08:42 PM
If you are using anything over 34.5 grains of H4198 and not jamming your bullets, you are cramming the base against the powder column, and that will change each OAL. A larger bushing only makes it worse. I am using a .323 bushing and if I load more than about 2 days before a match, the OAL's differ. I jam my Euber 118's .013 and that works for me. No vertical.

skeetlee
08-01-2010, 08:43 PM
Thanks fellas there is a couple good thoughts here. I am using a .325 as its the only one i have. i will buy a .324 and try that. Also i may be still fighting this rifle a little. I have a NF 42 power scope and the darn thing keeps hitting my eyebrow if i dont put the proper shoulder into it. The rifle is set up for the weight of the NF and tom glued the pad on so im not real sure if i can change it and still have the proper balance, but i am going to look into that. I love the scope but the eye relief is just to short for the recoil this rifle has. I will say that i was being very carefull and really paying attention to how much or how little shoulder i was putting into the rifle while shooting. I was also keeping my head still and really trying to shoot good groups.
Just about everyone says the 30BR like a lot of jam so maybe i need to try that as well. Im my mind to much Jam is stress on the cartridge so i dont like to do it, plus i have found that all the ppc barrels i have had like the bullets about 5 to 10 off full jam. Maybe im not thinking about all that the way i should? I figure if the action doesnt need any stress then why would the cartridge what stress on it?? Lets see what else? Oh, Im already at 34.8gr of powder should i try to get 35gr in the case? Seems like a lot, but i havent had any pressure signs, now i think about it. The load would definitely be compressed. We will get it figured out one way or another! Thanks a bunch! Lee

savet06
08-01-2010, 08:48 PM
I would also suggest trying to jam deeper into the lands. The 3 30br's that I have shot all liked a .025-0.030 jam with a .324 bushing. I got some good input from Al Nyhus and Randy, and tried that recipe in each of those guns with good success. I was very recoil sensitive and had to go to the Past recoil pad and a pin style of shooting and have had some success with it. It will induce some vertical if I am not careful with my technique, but my scores/groups have become much more consistent since I switched styles.
Mike

Pete Wass
08-01-2010, 09:58 PM
Some barrels won't let ya reduce the vertical. One that I had would do no better than a bullet of vertical until I had a tuner installed. I was easily able to take the vertical out with the tuner while using the same load paramaters.

It has been my experience that the majority of my 30 cal barrels shoot best at .006 into the lands. That .006 is measured from where one can barely see land marks on the bullet. I manitain that one is simply lucky finding a tune if they just jam their bullets in without knowing precicely where the bullets are positioned.

skeetlee
08-01-2010, 09:59 PM
I have read a lot of different post were fellas talk about jamming bullets. I always wonder what there definition of jam really is. The same goes here on this post. To me jam is the max length i can seat a bullet before the rifling pushes the bullet deeper into the case. At least thats what i think happens?? When someone suggest to jam 30 thou what does that mean? Does that mean your placing your bullet 30 thou past push back length?? You know maybe im not even thinking about any of this in the proper way. Is it true that you can only seat a bullet so far out before the rifling pushes the bullet deeper into the case, or can you actually (with enough neck tension) push that bullet farther forward into the rifling?? I guess i figure that i have about .030 of land contact point before i am completely backed out of the lands and i have found on all my rifles that somewhere with in that .030 (approx) area is where the rifle shoots best. I have been shooting some of George Ulrich little uglies BT bullets in my ppc and they like to be in the lands about .005 and it also seems to me this 30BR is about the same?
I have a real good friend here that i talk to on the phone quite regularly and after talking all this over with him, im first going to move my scope forward (so i dont keep getting hit) and im going to move the front/rest bag back down the stock further. I may also try a softer front bag. I may have an issue with the stock acting in a spring board type situation. One other thing i discovered was that i was really putting the squeeze on the sides of the stock to try and slow the recoil down, and that could cause some vertical as well. So i have a few things to try. I appreciate everything you fellas do for me, and im glad to be a part of all this. Have a safe week, and i will post after i get a chance to go shoot again! Lee

abintx
08-01-2010, 10:09 PM
I shoot my 13.5 lb Heavy Varmint 30BR ... Free Recoil ... just as I do my LV 6PPC. Both have provided excellent results with this method.

When you hold your 30BR, how do you measure your shoulder pressure? How much pressure do you vary between holds?

That's the problem with holding. I was never good at judging hold pressure so I've always used Free Recoil. Much easier. More consistent.

Here's something to look at for more vertical solutions: http://www.6mmbr.com/verticaltips.html. :)

crb
08-02-2010, 12:22 AM
The bbl on my Metal Mayhem was bought used. I used my split case as shown below to locate the lands. Then I set the seater to put the bullet app .008" into the lands. .325 bushing. I use 33.8 gr of H4198 as this load shoots great in my other 30BR. I use 112 Cheeks bullets. The first time this combo was ever fired was in a group match back in March. I was low on 2 targets and 2nd on 3 more [ 100/200 group match ]. I anneal the cases after about 5 or 6 firings.

http://i114.photobucket.com/albums/n260/raayjayy/BRreloadingcasegaugeandjamfinder.jpg

jackie schmidt
08-02-2010, 09:15 AM
Skeet, if you are having trouble getting the powder in the case so that it does not push the bullet back out, just get a 8 inch drop tube and trickle slow. I get my 35+ grn load in my cases with no problem. And that is not a hot load. I have cases that have been fired 30+ times, with no problems.

There are a lot of ideas here, but the simple truth is you probably do not have the Rifle tuned as of yet. Both of my barrels, (1-17, 1-18), shoot at just over 3000 fps with the 112 BIB. 30's do stay in tune quite well when you finally find the sweet spot, but you do have to find it.

Many score shooters get lulled into thinking that their 30's are shooting really great because they can hit 18 X's, when the truth is they are actually sitting on a .280 tune. You are doing it the right way. Until you see a sub .200 agging capability, it isn't right.

There is probably nothing wrong with your bags, your Rifle handling, or any of the other things that shooters blame poor performance on, when the reality is the Rifle is simply not quite there yet............jackie

mks
08-02-2010, 12:01 PM
Lee,
It could be that the dynamics of your rifle need tuning. A ladder test would determine if this is a problem. Load two sets of rounds from say 33 gr to 35 gr in 0.2 gr increments. Shoot each round at a separate bull to make it easy to measure its vertical position. (Two sets allow you to see if the results are repeatable.) If you get a graph like below, you are in luck. Use a load in the middle of the range that minimizes vertical, like 33.8 gr or 34.6 gr in this graph.

If you don't find any flat "steps" in the ladder, first try varying how much the forend overhangs the front rest and how close the rear bag is to the toe. If these don't work, then try moving weight around. Try moving weight from high in the butt to low in the butt. Try weight in the forend. Try a DanH "possum belly." (I'll let Dan explain this innovation.:D) Try heavier or lighter scope and rings.

To put rifle dynamics in perspective, consider that an ES of 50 fps would be pretty good for a 25 shot match. A 50 fps difference will cause 0.1" of vertical at 100 yards for typical 30BR ballistics if the barrel is stationary. If the barrel is swinging up at the right speed when the bullet exits, this vertical can be essentially eliminated. If the barrel is moving the wrong way, the vertical could be doubled or tripled. The ladder test is a good tool to see whether the dynamics of your rifle are working for you or against you.

Cheers,
Keith

abintx
08-02-2010, 12:43 PM
Skeet, if you are having trouble getting the powder in the case so that it does not push the bullet back out, just get a 8 inch drop tube and trickle slow. I get my 35+ grn load in my cases with no problem. And that is not a hot load. ... jackie

In addition to the long drop tube,

isn't a good part of the reason you're able to get more powder into your cases is because you blow your case necks out and forward when fire forming [instead of mechanically necking them up which shortens them]???

And, with this method, and a longer reamer that provides a chamber length of 1.550" and hence a longer trim-to length, you arrive at a finished case that provides more powder capacity???

:)

skeetlee
08-02-2010, 06:54 PM
When you fellas tune your rifles do you look for powder charge first or seating depth? I just dont want to be doing to much at once. I am looking at powder charges first with the bullet about 10 off full jam. Like i said above all my rifles (ppc) have shot best in this area so that were i started. Another thing i thought about is my barrel. This Krieger barrel only has about 95 rounds on it now. No signs of copper even in the least but can it take a few rounds for it to settle down?
The only other thing i worry about is my stock. I used a Robertson brx LV stock for this HV 30BR. Tom weighted the butt end but the forearm is pretty hollow. Maybe thats nothing, but im wondering???
I moved the stop on my JJ all the way out so that gained about 1.5" on the stock. I will try that, and i will loosen the grip on the stock. I think i will also start over with the loads. I think i will load 33.7gr with 5 rounds bullets jammed hard and 5 about 25 off the jam and see what happens. what ever looks best i will work from there. There again though should i work seating depth or powder first? Thanks Fellas, i dont know what i would do with out you all!! Lee

abintx
08-02-2010, 11:08 PM
Powder first.

Here's a guide I use, but only as a guide. Something I summarized for my use. Taken from Precision Shooting Magazine, The Benchrest Shooting Primer, Page 197.

"Scanning" For The Right Load …. by Lee Euber

1. Polish bullet with steel wool. Initial seating depth achieved when bullet is marked by all lands. [Tony Boyer likes to see a “square.” My added remarks.]

POWDER

2. Load 3 cases in a low grain load. Increase each 3 case load by .5 of a grain, and then shoot. Increase loads until primers show pressure.

3. Identify shots that grouped well, not so good, and then good again.

4. Pick load that shot the best. Load 3 cases with .1 grain less, and 3 with .1 grain more, for another comparison.

5. After picking charge for use, load 30 cases with the same powder charge.

SEATING DEPTH

6. Load the 30 cases in groups of 3, increasing the seating depth from touching the lands to jumping about .040 of an inch, in increments of .005 of an inch.

7. Shoot all 30 rounds without cleaning or clean after each 10.

8. Use ONE fouling shot after each cleaning.

9. Select load that shot best. Load 5 cases with that powder charge and seating depth.

10. Load 10 cases, 5 with seating depth .005 less than benchmark figure and 5 with .005 more.

11. Can compare more than once or change seating depth by .001 or .002.

12. Once you’ve picked the best seating depth, load 15 cases at that depth.

POWDER

13. Check first test by varying charge by .1 grain, for each 5 shot group.

14. Shoot in a medium wind condition, letting the gun do the work.

SEATING DEPTH

15. After picking the best load jumping the lands, compare it with the load that touches. Compare these loads again and again, on different days, in varying conditions, deciding which one is best.

16. If it doesn’t shoot to your satisfaction, restart with a different powder.

NECK TENSION

17. If you decide on the load that puts the bullet in the lands, be sure neck tension is tight enough to hold the bullet uniformly. :)

savet06
08-03-2010, 10:34 PM
I have read about jam, jam-seat and so on, but I have never been able to wrap my head around such an arbitrary measure as your neck tension will cause the jam length to differ with each round.
What I have done, and this may be totally unnecessary, is to seat a bullet long and chamber the round. Take the case out, and polish the bullet with 0000 steel wool and rechamber the round. I then look at the bullet and see if there are any marks on the bullet. If some exist, I will polish again and rechamber. If no or very small marks exist I will measure the OAL with a comparator tool.
I will then pull that bullet and seat it 0.001 longer than my measured OAL. If no marks exist I will keep going out until I see marks, and this will be the start of my jam length.
In essence, as long as you know where you are starting, and you are, as Pete states, precise with your placement with each round the jam distance is somewhat arbitrary. However, where the real issue arises is when we are all trying to talk the same language and our reference points are different. What it all comes down to is, as Jackie states, where does the gun shoot best.
It's really about the process more than the numbers, I guess.
Mike

Pete Wass
08-04-2010, 01:01 AM
SQUARE MARKS:

I screwed on a new barrel tonight and went about the process of finding where the lands touch the bullet. I seated a bullet long and jamed it home. There were BIG square marks on the bullet. It took .025 to push the bullet back far enough to where I could faintly see the lands just touching the lands. How in the WOILD can anyone, with any degree of precision and knowledge of where they are, rely on SQUARE MARKS for anything?

Boyd Allen
08-04-2010, 02:41 AM
I think that the old square mark thing came about at at time when bullets had single radius ogives of lower numbers, and may also relate to which powder was in use by the person making the recommendation.Today with the advent or double radius ogives that have higher numbers, that are closer to parallel to the typical 1.5 degree per side leade angle, the way that marks progress as bullets are seated progressively longer than touch, different truths may emerge as to what sort of marks are likely to be an indication of a good place to start when working up a load. In my limited experience (6mm short bullets) single radius ogives, around 7 give good results with marks that are perhaps one third to one half as long as wide, and double radius that are around 9 in the area of marking seem to like marks that are longer than wide, something on the order of three times. I have been told by Del Bishop that the latest double radius design that he is making seems to perform well at a variety of seating depths, including being jumped. Randy Robinette also mentioned that he thought that these sort of ogive shapes were easier to tune because of their being less critical as to seating depth. This is not to say that older designs are not as accurate, just that they may be more demanding in regard to seating depth. Is anyone making a double radius design in light .30 cal. ?

Pete Wass
08-04-2010, 08:24 AM
I don't know what that means, Double Radius :( . I read what you said above but it still didn't develop a picture in my head. :confused:

abintx
08-04-2010, 11:17 AM
I don't know what that means, Double Radius. :( I read what you said above but it still didn't develop a picture in my head. :confused:

Here is what Bart Sauter has to say about one of his bullets called the Wedge:

"A large, tapered bullet, which measures .2439 on the pressure ring and starts large on the body at .2438 and quickly tapers off. It is a double radius bullet which starts as a 9 ogive in the back and then blends into a 6.5 in the front. It is a short bearing surface bullet."

The bearing surface is the area in front of the bullet's base. [The picture below shows bullets on the left that have more bearing surface than those on the right]

Below is a picture I got from one of Speedy's articles that should help with visualization. Art :)

Pete Wass
08-05-2010, 07:48 PM
I must say, I have found the straight walled bullets easier to tune in all the 30's I have had so far. Give me a straight 7 any time.

Fla mac
08-07-2010, 01:25 PM
All,
I have a new barrel on my Stolle Teddy HV and I need to ladder it to find were it shoots the best. I have been shooting (free recoil) it with 33.5gr. and 118 gr. bullet. The OAL is about .030” into the lands. I ‘m not pleased with the performance that I’m getting so I’m starting over for scratch. I have the OAL at just touching the lands, now I’m loading in .3 gr. steps from 33.5 to 34.7. I set my scope to shot 3” to the right of aim point and change the target after each group. I have the same aim point with all groups shot. Will .010” change in OAL be to much in each steps after the first set of firings (just touching).

john
Mims, Fl

skeetlee
08-07-2010, 04:01 PM
FB
I didnt mean to offend you or any one else here sir. Just a little friendly conversation, thats all. I go shoot as much as i can, but i am raising a young family, and i have a full time job, thank god!! I like to talk and read with these fine folks here, so i thought i would share a little about my experience. Lee

jackie schmidt
08-07-2010, 04:28 PM
Skeet, Francis gets cranky because it is probably still snowing up where he lives.:D

TestPilot
08-07-2010, 04:31 PM
What's your barrel length?

Fla mac
08-07-2010, 05:29 PM
TestPilot
22"
john

eww1350
08-08-2010, 05:22 PM
Skeet...hopefully your gunsmith made a seating depth gage from a piece of your barrel...if yes...then measure a sized case (no bullet)...then seat a bullet about .030" long (on a loaded case)...shoot a 5 shot group...(powder charge of 33.5 grns H4198)...if you have vertical adjust the seater to .025" jam...again same powder charge...continue reducing the jam by .005" until you can see improvement in the amount of vertical...try to avoid big jumps of .010-.020" in seating depth adjustments...powder charge is less of an influence than seating depth...and with temperatures in the 80-90 degrees range the 33.5 grn load will give you enough velocity to determine where the vertical is coming from...
once you have reduced the vertical to the lowest observed...then check your front bag...soft is OK...hard as nails is BAD...rear bag...hard as nails OK...soft NOT good..

let me know if this helps...it is how I got rid of the vertical problem in my 30BR...


Eddie in Texas

skeetlee
08-15-2010, 02:10 PM
Just a little update on my 30br. All seems to be getting better. I slid the stock further into the front rest about 2" and softened up the front bag side squeeze. I didnt get to shoot very many groups today but the few i did shoot didnt have any vertical. I am sure that this barrel likes the bullets about 30 off full jam. I did have some lateral movement in the groups today but the winds were though so i cant say for sure if that was the load or the wind. I thought my wind calls were good however. So im getting closer. I still need to find the powder charge but like i said above i am more than confident my seating depth is going to fall some were between 20- 35 off full jam.
If the lateral movement wasnt wind today, wouldnt that indicate to much or possible to little powder? thanks Lee

Pete Wass
08-16-2010, 10:09 AM
It indicates your barrel is spitting the bullets out sideways in it's vibration. Try going up with .002g of powder for three sets of loads and if that doesn't work, go back to your brginning load and load three sets with .002g less of powder to see if you can find the round hole you are looking for.

Perhaps I should have said the bullets are exiting instead of spitting them out; all amounts to the same thing though. WEIGH YOUR CHARGES.

jackie schmidt
08-16-2010, 12:00 PM
Pete, I was all ate up on weighing charges last Winter, but just said to heck with it as it got to be such a hassle.

I have had my best year in the last three this year, and have not weighed a charge in a match yet. I just went back to the same technique that I used for years while throwing charges.

I know this goes against the usual of removing every variable, it's got me stumpted as well.

A great barrel and some great bullets solves a lot of these problems. On my 6PPC Sporter, I have chambered 4 barrels up in the past month, and consider one worthy to take to a Region Level Match. I am fortunate to have two outstanding 30 caliber barrels for my 30BR HV.......jackie

Pete Wass
08-16-2010, 02:41 PM
It's the barrel Jackie. I have a note book in which I record by drawing in what the groups look like when I am testing. Time after time after time and I can show you or anyone else who wants to look; with most rifles and barrels as little as.002g of powder will open up the group and as little as .003 of seating depth,; be happy to show to you any time.

I have had some barrels over 11 years of shooting that weren't as fussy but they are rare birds. This is why I meticulously weigh and check seating depths, I don't have one of those barrels that will digest anything right now and I suspect most folks who aren't easily able to get a rifle to shoot don't have one either. The fussy ones can be made to shoot but they demand very close attention to their digeestive system; from what testing and shooting I have done, anyway.

Now, don't be shooting that barrel a lot just because it shoots so darn good !

skeetlee
08-16-2010, 08:00 PM
This is my second 30br barrel. The first was a bartlein 17 twist that shoot outstandingly well with just about anything i put down it. This one is a bit different but i do believe it will shoot just fine in the end. Actually i learn more from barrels like this one than i do from the ones that shoot right away. Im getting closer but just not quite there yet. Like i said above it looks like it likes the bullets backed off the jam 20-30 thou. I really dont have a grasp on the powder charge yet though. Next outing im going to try 35gr. I wish i didnt have to go that high, but i am willing to do whatever i have to to do. I am also going to look around the 33.5gr area. I also wish i had another type of powder to try. I have had excellent results with Benchmark in the past but its pretty darn slow. Maybe with this 22.5" barrel i will get some better velocity??
We shoot the 30br out to 400 yards yesterday in our local Varmint match. Those short fat 118gr bullets sure dont do very good at that distance. LOL!!! For 100 and 200 yards i love it but much farther than that it becomes a choir!!!
Thanks fellas for all the replies. this has been a good topic, and i have enjoyed the read! Have a good evening gentlemen! Lee

jo191145
08-16-2010, 09:44 PM
Lee, I agree 100%. Its the finicky ones that teach us.

Just spent four months off and on with my first 30BR. Built on a T&T'd Savage action with a 2oz. trigger. (I know, everyone hates Savages cept me)
Besides the choice in action I followed all the rules. Consistently the worse shooting semi custom gun I've ever had. I changed everything including action on that Benchmark barrel several times and nothing worked. Changed bullets, powder, primers, jammed to jumped and nothing worked. a good load shot .5 - 1 moa. Out of the node was 2 moa.
Obviously something was unhappy besides me. Very close to smashing the whole shebang over a rock.

To make a long story short in an act of desperate frustration I switched from the normal .003-.004" neck tension and went to .001"
Only had a handful of semi suitable bullets left to fire. 135gn SMK's. Was'nt about to spend real money on real bullets for a 1moa gun ya know.
Darned if that barrel did'nt start shooting groups all of a sudden. Ran out of 135's using Benchmark at 35.2 gns and .007" past just touching.
That last group was .347" at 200 yds. Velocity is definately slow at 2680fps.
Confidence is high enough to have ordered some 115gn Bergers for testing and just in case some more 135's also.

Pete Wass
08-17-2010, 01:25 AM
The best node for these rifles seems to be 2960 to 3000 fps. Those slow nodes sometimes shoot well initally but the wind will eat your lunch. You need to consider faster powder. Most people use H-4198 and N-130 is a very good one. I am currently finding great results with Re-7. Most of the barrels I have or have used seem to like to have their bullets around.006 into the lands from where you can just barely see land marks on the bullets. I know people do a lot of different things to tune , I am only sharing what I do. I also use a lot of neck tension.

You might try some Speer TNT's . They seem to shoot very well in the 30 BR or any thirty, for that matter.

jo191145
08-17-2010, 09:27 AM
Thanks for your thoughts Pete. Trust me I did my homework and read the literature. I shot over 400 TNT's starting with initial fireforming of 100pcs of brass and H-4198. Tried another box of Lapua 123gner's. Hornady 110 V-Max. 135SMK's and excuse the infraction even some 147gn Winchester FMJ. A bullet not worthy of a slingshot but I did it anyway.
Shot H-4198, RL-7. Tried a little N-530 with the heavy stuff. Even tried Ramshot X-Terminator with the 147's. Did'nt switch to Benchmark until I tried .001" tension.

These were pills I already had on hand. I figured after fireforming the brass with 100 TNT's I'd order up some real bullets. Even during fireforming I knew something was wrong so I never bought decent bullets for the gun. The gun was just shooting globs for groups. Even with the nonpedigree bullets it should exhibit some degree of repeatable accuracy. I've launched most of those pills out of a 13 twist Kreiger barrel in 308W so I knew what to expect.

Never saw any repeatable accuracy until I switched to .001". My only quess is my neck turning is not exact enough. Its not as precise as you pro's would do but it looked at least OK to me. I'm gonna look up an old machinist friend of mine and have him mic the stuff up, get some proffesional measurements, oponions and maybe even clean it up on a lathe with an oversized mandrel. I intentionally overcut to .0095 neck wall already tho. Best bet might be order some already preprepped at this point.

Once I figure out why .001" is the only tension that works for me, hopefully correct the issue, then perhaps I can proceed to find a suitable load with a suitable bullet and suitable powder.

Yep that big honkin 135 is slow. But the BC is a tad higher. With .001'' and a standard Robinette reamer it would be a huge challenge trying to make it go faster. Providing it can even maintain a somewhat competitive degree of accuracy. The puter says at 2680 it outperforms the 115 Berger at 3000fps.
Of course the puter never hands out any wood:D:D

jackie schmidt
08-17-2010, 12:00 PM
"the (com)puter never hands out any wood"

That's the truth. I remember a couple of years ago, Greg Anderson of Pro Stock Fame, after a round loss, was lamenting about a motor that just did not seem to be up to par, the dyno numbers had been really good. But, as he reminded the interviewer, "we don't race Dynos".........jackie

jo191145
08-17-2010, 12:31 PM
We don't race Dynos..... Funny but true Jackie. Of course at one point or other we've all been tempted to shoot computers. :D