PDA

View Full Version : Pressure Need Answer



Hombre0321
06-27-2011, 09:13 PM
Guys I went to the range today, still working up a load for my 6 MM BR. This load was most accurate load so far shooting into a group at 400 yds that measured 1.09 Horz X 1.19 Vert. Trouble is the primers--- all extracted fine, but this can't be good see pictures and let me know what you think.

Load was 28 grains of Benchmark, neck Sized lapua Brass, Remington 7 1/2 primers.
temp was 90 to 94 degrees.

I did have a few of these same load with the exception of 28.2 grains of Benchmark. In these the primer is punctured another words you can see air when looking through the case. I only shot two of these and wouldn't shoot anymore.

Roland

http://imagehost.vendio.com/a/19898374/aview/Picture_040__Large_.jpg

http://imagehost.vendio.com/a/19898374/aview/Picture_036__Small_.jpg

http://imagehost.vendio.com/a/19898374/aview/Picture_035__Small_.jpg

http://imagehost.vendio.com/a/19898374/aview/Picture_031__Large_.jpg

http://imagehost.vendio.com/a/19898374/aview/Picture_051__Large_.jpg

XBBR Shooter
06-27-2011, 09:28 PM
What weight bullet????

Hombre0321
06-27-2011, 09:33 PM
105 Grain berger "VLD"

Roland

XBBR Shooter
06-27-2011, 09:49 PM
The 28gr load is way to hot - and BenchMark is probably not the best choice. But if you want to stay with it, start at 22 grains and work up to ~25-ish.

H4895, and Varget are better (and faster velocity) powders.

Charles E
06-27-2011, 10:41 PM
For the 6mm Br and 105s (more oe less), Jason Baney, who won the world open with a 6mm BR, said


You will most easily find happiness (I have found) with CCI450 primers and somewhere between29.5-31.5gns of R15 (be careful at that upper end!)

If you use Varget, it seems to respond best with hot loads, no matter what the chambering.

Hombre0321
06-27-2011, 11:30 PM
Guys thanks for the information...

XBBR, No sir I am not bound to Benchmark in any shape or form, I learned long ago to let the rifle tell me what it wants and never had any success trying to tell the rifle what it was going to get. This Benchmark load came from the Hogdon manual and it list 26 grains as a starting load and 28 grains as a max load for the Sierra 107 grn HPBT. Thought that would be fine for the 105 grain Berger VLD. That obviously wasn't correct. Thanks for the response, I really do apprecate any input what so ever.

Charles, I do have a couple of thousand CCI 450's and they were on my list to try I just grapped the Remington 7 1/2 because they were close to hand. The first loads I tried were the Varget loads because I had read so much about that powder in the 6mmBR. It simple shot more of a pattern than a group for me so I switched to Benchmark because I found the load DATA IN THE Hodgdon book. It shot pretty good from the get go, but every load I shot of Benchmark did show some primer deformation. I should have quite then but the results showed promise. As my old CO used to "say live and learn and die a damned fool."

Charles this is the second time you have mentioned or furnished me with information about RL15. There will not be a need for a third. There is a supplier about 50 miles from me ( I live kinda out in the country a ways) and I will be over there tomorrow to purchase a couple of pounds of RL15.

Thanks once again Charles, this is getting to be a habit for me-- Saying Thank You to you!!

Roland

Charles E
06-28-2011, 10:21 PM
Roland, I don't shoot anything that uses Reloader 15, but I have and continue to shoot chamberings that use Reloader 22 and 25. While great powder, the Reloader series, made by Bofors (sold as canister powder by Alliant, Norma, and one other company), is temperature sensitive. Changes in temp mean you should change the load. Record keeping is in order. Also check the lot-to-lot consistency. Alliant (Reloader) seems to use the full 10% variation allowed for canister powders. With those constraints, they are great powders.

Reloader 17 is Swiss-made (not Bofors). It is probably too slow for your chambering, and I don't know if it is temperature sensitive or not.

I have shot Varget in .223 and a .30x44 Hunter rifle. I know a fair number of guys who use it in 6 Dasher. It is my experience, and theirs, that Varget tightens up when you go to higher pressure. Not unsafe, but high. At lower pressures, it hasn't performed so well for me. On the other hand, it is less temperature sensitive. Not immune, but far less than the Reloader line.

There have been reports that the new 8208 XBR works well in the 6mm BR. And some of the Montana guys have been successful with H4895. 4895 should be less temperature sensitive, too.

You don't need to thank me. When my father was a boy, the neighboring farmers, mother and father, were killed in an accident. Each of the neighbors, including my father's family, took in a kid, and worked their farm enough to pay the taxes and bills, so when the kids grew up, they'd have a place. This was the depression, and that's what people did. We all need help from time to time, and whenever possible, better neighbors than government. I'm sure you've helped others out in your time.

jackie schmidt
06-29-2011, 09:07 AM
Let's look at something else.

What is the condition of your firing pin and it's clearance in the firing pin hole.? Since there seems to be a generous amount of outside radius remaining on the primer, (they are not that flattened), indicates that the real culprit is a firing pin with exccessive clearance.

Difficult bolt lift, case web swelling, and and the actual flattenning of the primer are much better indicators of elevated pressure than primer cratering. I see Factory Remingtons with Factory Ammo do just what your Rifle is is doing.

What is the velocity. There are many shooters that put 105 grn bullets in 6BR's flat on 3000 fps with no ill affects what so ever. When I did my Rail Gun Test for 6mmbr.com., 3000 fps was the sweet spot for most bullets, paticularilly the 105 Berger VLD. I loaded them with CCI 450 Magnum Primers and enough reloader 15 to hit a flat 3000, and it produced a .180 five group agg at 200 yards.

Take a good look at the firing pin and the firing pin hole...........jackie

XBBR Shooter
06-29-2011, 11:11 AM
"... I did have a few of these same load with the exception of 28.2 grains of Benchmark. In these the primer is punctured another words you can see air when looking through the case. I only shot two of these and wouldn't shoot anymore.
Roland"

Some years ago (when I was a young pup), I perforated a primer or two in a bench gun I was shooting. I was shooting CCI BR-4's at the time.

I never paid attention to it, other than lowering the powder charge.

Over the years, I had misfire problems - light strikes, misfires that needed to be struck a second time, short hang fires, all kinds of problems.
I went to another primer, but that didn't help. Then I decided that the firing pin spring must be bad, so I replaced it with one that was 6 pounds heavier than new factory. That didn't help.

So, eventually, the gun wound up in the rack, collecting dust.

About 4 years ago, a friend needed a spring (same gun), so I offered him the spring from my "sleeping rifle".

I pulled the bolt apart and pulled the spring, and I decided to clean the bolt (cuz now, I had one of those spiffy nifty ultrasonic cleaning thingies).
So after 10 minutes in the ultra sonic cleaner, I turned it off and removed the bolt body...
... and there, in the bottom of the pan, was the little disk that was punched out of the primer.

I looked at the firing pin, and on the side of the stop ring, was a bright shinny mark - the disk had lodged on the side of bolt and was dampening the pin fall all those years.

I replaced the old spring (Rule #1 - never EVER throw anything out ;) ) and the rifle shot fine :) :) :)

The moral of this is:

1 - Learn from other people's dumb mistakes (mine ;)

2 - Get those punched disks out of your bolt, or they will come back and bite you in the ass at the worst possible moment (when you are about to win the biggest match of your life!!)

HovisKM
06-29-2011, 12:30 PM
I agree with Jackie. Also, you might want to check how much your sizing your brass, you could be oversizing a little also, that will cause this condition.

Hovis

Charles E
06-29-2011, 03:03 PM
Jackie & all:

From another post by Roland, this is a Stiller action of some sort. I believe it is one for which Stiller also made the bolt, i.e., not a Predator. I guess while even Jerry can let a problem slip out every 100,000 or so, and it is worth checking, I'd put it pretty far down the list.

Vern
06-29-2011, 05:55 PM
If Charles is correct and its a Stiller action then it shouldnt be the firing pin. But everything Jackie said is also correct.
I used to have a panda (older panda) that did the same thing. I couldnt get anywhere near the powder loads that everyone else talked about shooting.
I did find that I could shoot a little hotter with some primers than others but in the end it was a firing pin to hole size issue.
The reason some primers worked better than others was they have harder cups.
Do a search on German Salazar and you will find some links to some tests he has done.
I know Stiller IF BIG BIG IF,,, if it were a problem with the bolt he would surely take care of it without any problems.
You could call and talk to either him or Russ and that should at least eliminate any issues or questions on the action or bolt.
XBBR is right about making sure you get the pieces of metal out of your bolt.

jackie schmidt
06-29-2011, 07:24 PM
If it is a Stiller, then unless someone has screwed with it, what I mentioned would not be the problem.
Those primers still seem to have a generous outside radius as compared to the gosh awful cratering he is getting. Heck, we shoot close to 70,000 psi loads in Farleys and Stiller Actions,and while the primers look like pancakes that have been stomped on, they sure don't have that sort of cratering....jackie

JohnsonGunsmith
06-29-2011, 07:37 PM
I had a safe load in a 6 dasher blowing remington primers just 2-3 weeks ago and went back to the CCI primers and boom problem solved. I even reduced the load a full grain and a 1/2 but remington primers were still peirceing about1/2 the time! The CCIs would take more pressure and not show signs of flatening or anything even after goint to a load that was pretty hot. I never went back to see what was going on as time is an issue right now but I am wondering if this is just a primer problem with the remingtons?? anyway good luck and I would try CCIs or federals to see if things change.

Vern
06-29-2011, 07:41 PM
I know this might be a useless question for someone who has not responded. But I am lazy and dont want to look it up.
What is the hardest cup out there?
I know German had it in his tests.

cdupuy
06-29-2011, 11:15 PM
jackie: from the pictures it appears that the FP is too big a diameter for the srp and I agree with you about the pin and bolt hole being off.
Clarence

Mike Bryant
06-29-2011, 11:35 PM
Hard to tell from the photos, but the fourth photo looks like the primer is backing out of the primer pocket. If fired primers are not below or even with the case head and are backing out to where they are above the case head that can be a sign of excess headspace whether in the chamber itself or in setting up the bump back on the shoulder with a resizing die.

alinwa
06-30-2011, 02:04 AM
Hard to tell from the photos, but the third photo looks like the primer is backing out of the primer pocket. If fired primers are not below or even with the case head and are backing out to where they are above the case head that can be a sign of excess headspace whether in the chamber itself or in setting up the bump back on the shoulder with a resizing die.

looks to me like that bump in pic 4 might be the eruptation of brass 'struding into an oversized firing pin hole......

I happen to know of a company that does fine work in this area > http://www.bryantcustom.com/pricelis.htm < and could perform this service for around a hunnerd buck, plus shipping.....

:)

al

Hombre0321
06-30-2011, 06:00 AM
Guys thanks for the comments and advice. For the record this is a Stiller, Viper, Drop Port action. The rifle is new and I recieved it from the smith only about three weeks ago. It is a Hart barrel and while I do not have a go-no go gauge. I believe the headspace is .002 or maybe .003, hard to tell exactly with out the gauge. I checked it with the old fireformed case with a piece of .002 tape on the back of it, this would not chamber nor allow the bolt to close. I know this is not the proper way to check such a thing but it is all I have at the present time.

You guys are correct the metal from the primer case is flowing back around the FP and forming a crater. No primers have backed out of any of the cases at all, and not all of the primers are flat. Some are somewhat flat, and some are not flattened at all it looks like. One case and only one had a shiney spot on the back of the case. Three of the cases had punctures thru the primer cup.

Today I loaded up some ammo using the RL15 and 20 more with the Benchmark powder load of 28 grains that showed the most signs of whatever is going on just to see if it was indeed the Benchmark or maybe some other problem all together.

The day Monday, that I had this problem rear it head was pretty hot. The temp was 97 degrees humidity was right at 65% and the sun was shinning right down on my shooting position, which had lost it's top or roof in the last tornados we had here a few weeks ago. I had set out 6 targets and shot 5 shots into each of those targets for a total of 30 shots over a time span of around 25 or maybe 30 min. The barrel was very hot and while it was touchable you could not leave your hand on the barrel for 10 seconds.

Today I wanted to elemenate the heat from the equation. My reloading room is an adition to my shop were I keep three old classic Chevys I have owned for awhile. The reloading room has a window on the pasture side and while I do have neighbors, If I am not too noisy I can fire a "FEW" shots from inside the room into a Berm I have at 100 yds. The reloading room is air conditioned and I started the air about three hours before I went out to shoot. When I started shooting the temp inside the room was 67 degrees.

I shot the RL15 loads first to warm the barrel, 20 shots and you could easily still grap and hold the barrel for as long as you wanted, it was hot but not so hot that you couldn't hold onto it. I then shot all 20 of the Benchmark loads. There was no damage at all to the primers, no cratering, no flattening, the chambered and ejected easily.

I then took the rifle and set it directly into the sun while I loaded 20 more of the Benchmark loads and 20 more of the RL15 loads the RL15 loads ranged from a low of 29.5 grains to a high of 31 grains. I shot the RL15 first to once again heat up the barrel, the temp was 96 degrees, The I then shot 5 of the Benchmark loads the barrel was once again very hot, you could not hold onto it for any length of time at all, maybe 10 or 12 seconds. All 5 of those primers were cratered badly, as I sat them on my reloading bench they do not set flat the have a lot of lean to them the primer crater is that big. Using a feeler gauge it feels like .025 or so at least. The primers are like before some are a little flat and some dont appear to be at all.

While the barrel was still very hot I shot 5 of the RL15 loads of 31 grains. There were no pressure signs that I can see, no craters, no punctures, no flat primers. On 2 of the cases at the primer dimple while it does not look anything like a crater there is a line around the dimple, like some very small amount of metal was rolled over for lack of a better word. It is not very noticable you can not feel it with your finger nail at all, a very sharp knife will not hang on it and I only found this line with a magnifying glass.

If any of that gives anyone food for thought I sure am open to hear them........

Thanks Guys !!

Roland

f d shuster
06-30-2011, 07:08 AM
In addition to all the other suggestions, you might want to consider the chance that a build-up of carbon fouling could be the problem. Easily determined with a borescope. Two Summers ago I suddenly began getting harder than normal bolt lift after firing, and blew 2 primers. All with the identical load I've been using since 1998 in one of my 6ppc's. Went into the bore with my Hawkeye and found a heavy build-up of carbon. My fault. I had just installed a McMillan Edge stock, it began shooting really well, & I let my shooting get ahead of cleaning requirements. JB'd the bore, carbon gone, end of problem.

Mike Bryant
06-30-2011, 11:58 AM
If it's a new Viper and it's blanking primers, call Stiller. If it has a .062" firing pin hole and it's blanking primers, pressure is too high. You did the right thing by quitting shooting after it blanked the primer. I've had several Jewell triggers come into the shop that have failed from blanked primers. When the primer blanks, the gas is released inside the bolt forcing the firing pin back and then the firing pin spring drives the cocking piece against the top bar on the trigger. Similar to a small hammer hitting the trigger. BR case heads with small primers have been the worst of cartridges that I've seen with blanked primers. Jewell considers triggers that fail from blanked primers as being misuse and not covered under warranty. All the Vipers I've seen have had small firing pin holes. If it has a large hole it can be fixed, but with a new rifle, I'd contact Stiller first.

IndianaJames
06-30-2011, 01:49 PM
Just to make sure on the headspace, take a case you have resized and try chambering it with tape on the back...simple and quick.

Jim

Hombre0321
06-30-2011, 11:27 PM
George, MAN I havn't been talking to anyone... I already knew that heat is a major cause of short barrel life, but there lies a rub now doesn't it?

If you shoot a rifle in the heat ( kinda hard not to do that in the south in the summer time) you will in fact build barrel heat. If you don't shoot it because you don't want to damage the barrel, the rifle is then a "Club" and not even a good club at that. I already have enough clubs so I'm shooting.

Barrels are an expendable just like bullets, brass, powder and primers. Thats a fact of life, I hope this barrel last for awhile certainly longer than the 295 shots down it so far, but what will be will be.

I try to shoot practice just like a match will be, I started doing that when I started shooting Silhouette years ago. The match, and so far the only benchrest match I have seen or attended, that I went to last weekend the course of fire was as follows:

6 minutes to shoot unlimited sighters, my observation was that most shooters shot around 7 or 8 shighter shoots. The match winner shot 11.

10 minutes to shoot there first target of record, 5 shots.

There then was a break of about a minute before they recieved the commence fire to shoot there next string of sighters they had 2 minutes for those. Most of the shooters shot 4 sighter shots in that period, the match winner shot 8.

They then had 5 minutes to shoot there 5 shots of record.

So they minimum number of shots taken by a competitor in the first leg of that match was 21 shots. The maximum shots taken was 29 by the match winner.

That was all in 19 minutes if my math is correct. The temp was 95 or so degrees and the humidity was very high around 65%. While I didn't go over to any of the rifles and feel the barrels, I am quite confident that they were pretty dang hot, certainly as hot as my barrel was the other day when I had my pressure problems.

So George shooting a hot barrel is just going to "Have" to happen sometimes. Should it be kept to a minimum? Absolutly !!! Can it be avoided all together? Not any way I can see....

Roland

Charles E
07-01-2011, 05:39 PM
Roland,

If I read all this correctly, the Rel-15 loads seem to be behaving as expected. You didn't say whether or not (or I missed it) you had switched to CCI 450 primers, or were still using the Rem 7-1/2 primers.

You also didn't say if Stiller built the rifle, or someone else. If Stiller built it, Mike Bryant's comments make special sense (Mike is a very good gunsmith, BTW). If someone else built the rifle and they're close by, a trip to their shop might be in order. Alabama is blessed with having quite a few good Benchrest gunsmiths.

While it would be well to track down he source of the Benchmark/Remington primer oddity, if the other load -- R-15 & CCI 450s is preforming as expected, I wouldn't worry too much. Remember with the Reloader series of powders, you will almost certainly need to take notes on load versus temperature, both to avoid blanking primers, and for best accuracy.

Charles

Hombre0321
07-01-2011, 11:15 PM
Charles, I did in fact switch away from the Remington 7 1/2 and went to the CCI450 primers. In the testing of the two primers in my post above I did load the Benchmark loads with the 7 1/2 primers trying to duplicate the orginal pressure problem, I did that easy enough.

Today after reading and reading a lot of post not only on this thread but on the feeding of the 6mmBR, I went back and revisted my Varget loads. When I first shot Varget it was not very good for me, so I moved on to Benchmark. At the range today, once again very hot and muggy with temp over 95 and my shooting position still in the direct sunlight, That I fixed but I explan later. The Varget load as well as the RL15 loads both shot very well. The best Varget load shooting at 400 Yds was 1.03 Horz by .94 Vert, three other Varget groups shot very well indeed not quite that good but almost. There were "NO" pressure signs at all with Varget None. The RL15 also shot very well and also showed no pressure signs at all, and it was HOT.

The rifle was not smithed by Stiller, I have had sevreal conversations with Jerry Stiller though and some about this rifle. It is my understanding that Stiller is almost exclusively consentrating on there Gov't stuff today. I have heard that it could take as long as 2 years to get a new action from them, dont know if this is true or not but I have heard that. The Smith was a Alabama guy, however and without going into any of the details having him look at the rifle is not an option.

The shooting position thing. Here in North East Alabama the Tornados of a few weeks ago really hit us hard. The level of destruction in some areas is very sad. At my home we lost 48 old growth trees, and I only have 8 arces. My closest neighbor who has 18 acres lost 150 trees. At the range I shoot at the storm ripped the roof off of the shooting postition. It is elevated and has 14 steps to get up to the shooting platform, I cuss every one of those steps every time I go. Trying to manuver steps two canes, rifle, scope stand and all of the other stuff we all seemed to need is a full days work for my old shot up and broke down butt. I usually am there by myself, thats good for me and they do furnish a Golf Cart to run down and change targets. The lady that owns the range just lost her Husband about 6 months ago to cancer, and she is having a pretty rough time. The missing roof is a problem in this Alabama summer. So today on the way home from the range I stopped at a local roofing company and contracted for them to run out there and install a new roof, Man gave me a very fair price after hearing the story.

That cost me a few dollars, but guys trust me on this after spending 30 years in the Marine Corps I learned long ago that of the things we all deal with on a daily basis money is the least important. Next time I will be in the shade......

Thanks Guys as Always Roland

Charles E
07-02-2011, 11:38 PM
Which reminds me . . . There are no steps at the Camp Butner range, but the shooting benches are not covered, except when someone brings a tent or clamp-on beach umbrella. At our board meeting this past winter, we voted to get pop-tops for all the benches, but the willing horse got flogged too much, so that hasn't been done yet. There is a stand of pine trees all along the south side of the firing line, so we can set up our loading/cleaning/sitting area in shade, but many guys also bring a pop-up top for there, too. If you're able to come, there will likely be one you can set up under.

There are rest facilities, but you have to bring food and water, so a cooler is probably in order. Town is only 10-15 minutes away. Any trash must be carried away by the individuals who made it -- no servants, and no trash cans at the range.

Shooters are nominally required to pull pit duty, but there are enough "standbys" to cover for anyone who physically can't work the pits, those of us pulling RO duty, etc.

If you can come, I think you'd have a good time, and get to see a broad range of equipment, and meet shooters with 15+ years of 1,000 yard benchrest experience.

* * *

Gossip wise: Alabama benchrest gunsmiths I know of are Col. Billy Stevens (Brundidge, Alabama), and Mickey Coleman (Greenville Alabama). Both are primarily short-range smiths. Col. Billy is a world-class shooter, and Mickey has a range (Rachel's Glen) as a part of his property. The 200 yard Southeastern regional will be held at Mickey's in October.

Edit:

BTW, While Billy was a colonel, he worked for a living . . .

* * *

Nice work on getting the widow's range covered. Consider any favors I've done you more than repaid -- I & some others now owe you a couple.

jmwcj8
07-10-2011, 11:14 AM
I have been fighting the same exact problem in a 6BRX and have been using RL15 the whole time with Federal and CCI primers.And what I found out along the way is this.I noticed that there was pressure when shutting the bolt on a empty chamber.And the front base screw was too long putting downward pressure on my bolt and keeping it locked in place off center just a touch.Then thought my firing pin was a bit long so addressed that.Then thought maybe I bumped the shooulders back to much so I light loaded and blowed all cases back out.And bumped shoulders back .001-.0015 went Thursday to the range shot 47 times cleaning after 15-20 and when I got to the last 5-10 started piercing primers again.This is using 31.8gr of RL15.I came back home that night and pulled the rest of the bullets I had and done the normal shoulder bump and all that is required and loaded back with 30.5gr of RL15 went to the 600yd shoot and it starts again.I sighted in piercing 1 primer went to record target piercing 2 out of five and having to recock twice to get two to go off.Then went to sight in again before other record target having one not fire and getting extremely aggravated went to other record target pierced one more then had enough primer parts lodged in bolt no more fire.I just quit because this was the second match I had to throw the towel in and I was not happy so I feel your pain.I don`t know what to do at this point.There is guys shooting 33gr in a brx and I can`t shoot 30.5 it is really disheartening.So any suggestions would help here as well.It is a 700 action though.

Mike Bryant
07-10-2011, 12:12 PM
Agree with George, the BRX's and Dashers need an .062" firing pin tip. Otherwise you'll be piercing primers. It happens too quickly and too often with these stretched BR cases.

Charles E
07-10-2011, 03:31 PM
I believe Jerry Stiller of Viper Actions was the pioneer in the use of the .062 diameter firing pin, & IIRC, that's what is used in the Viper.

The original poster is using a Viper . . .