pierced primers

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dozernomore

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south western ontario
Posted: Mon Jun 06, 2011 5:41 pm

alright,here is my situation
savage mdl 25 204ruger
1-12 twist
hornady brass
wsrp
h4895 27.3gr
40 gr V-max
3815 fps
third time NECK SIZED
I have shot this load for at least a hundred rounds or a bit more,and have had no issues,extremely good accuracy.Just this week I noticed a fired round with a primer that looked a lil different,apon further investigation I thought I would check out the rest of the remaining fired rounds from this batch of reloads and I noticed 3 out of 13 fired rounds have pierced primers.now one note that might be important is,that this batch was neck sized only and I beleieve it was the second time neck sized.I use the lee collet neck sizer.when I chambered my neck sized brass before powder charging and bullet seating,I noticed the odd one was a lil tight to chamber,some were to tight,so I put them in the flrs die.Is it possibble that my tight rounds are not chambering all the way due to stretched shoulder there for minimizing the space for the firing pin to fully extend there for piercing my primers.I am not gonna shoot this batch anymore and am gonna try my flrs rounds of the same load and see what primers will llook like then,,the load is below the hogdon max level,and if I do get pierced primer then I will shoot some factory 40gr v-max and see what happens,and if I get pierced primers then obviously it's a firing pin issue and I will need to go see my gunsmith.
ANY INPUT would be greatly appreciated..thank's in advance.
P.S. I love this gun and caliber..makes hamburger out of those pesky skunks here in
 
Do you have pistol primers in the house, and is there a possibility .... even a remote one...that you might have used them in your rifle cartridges ? 99 times out of 100, it won't make a noticeable difference, but you might have one of those very few rifles that's not reacting well to it. Pistol primer cups are made slightly thinner than rifle primer cups (according to my Sierra reloading manual).
 
Have you trimmed your brass at all? There may be a slight bit of extra neck length that is putting a little pressue on the outside of the neck resulting in more neck tension which will raise your pressures. You could try the guys over at Saubier.com too. They are the sub calibre guru's and talk of pierced primers all the time. Many of them have their firing pins bushed which lets them run higher pressures much more safely with no pierced primers.
 
Make sure the brass length is not over spec, if it is pressure will increase. Are you shooting in warmer temps than before? Rem and cci have thicker cups, and will not pierce as easily.
 
definitely don't have any pistol primers in the house,as far as trimming I alway's check to make sure they are not over spec.length.
and I am shooting in the same temperature as load development.
I do have some some cci bench rest 4 primers I might try,if I can't figure out anything else
 
Couple of possible culprits. This cartridge genterates near-magnum pressures.

The savage floating bolt head has a firing pin hole that is quite large (Your "Pierced Primer is from the cartridge pressure blasting the primer in the area between the firing pin and the bolt body) and by the way, those pieces of primer are likely inside your bolt... it would be worth taking it apart and cleaning it.

I would suggest switching to CCI 450 magnum primers. The cups are very hard, and are needed to resist the very high presssures from the cartridge. They are used by many F-Class shooters that use factory actions for cartridges such as the 6mm BR and its high pressures.

Your bullet seating depth may have played a role in higher pressres, seating long increases pressures. Neck tension and previous firing is unlikely a factor.

lastly, you must be darned near a compressed load with that powder. I use BL-C2 and get best velocity, best load density, damned easy measuring and it is easy to get in that tiny case mouth.
 
excellent input folk's thank's,,the brass in my bolt i never thought about,,I think I'm gonna see my gunsmith this saturday,and hopefully he can show me how to take bolt apart and clean the brass out.
 
Blanked primers can also be causes by weak firing pins or too much oil on the firing pin. Blanking is when the combustion pressures punch out round disks, push the firing pin back into the bolt.
 
Obtunded said:
I would suggest switching to CCI 450 magnum primers. The cups are very hard, and are needed to resist the very high presssures from the cartridge. They are used by many F-Class shooters that use factory actions for cartridges such as the 6mm BR and its high pressures.
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Good advice. I have always used the CCI 450 with my .204's because the cups are thicker than most others.
 
"...3815 fps..." That ain't right. 27.7(c) max loads of H4895 give 3741 fps. You sure about the load?
Oil in or on the bolt won't cause pierced primers. If it's only 3 out of 13, I wouldn't worry too much. Same box of primers?
Spaces after punctuation.
 
sunray said:
"...3815 fps..." That ain't right. 27.7(c) max loads of H4895 give 3741 fps. You sure about the load?
Oil in or on the bolt won't cause pierced primers. If it's only 3 out of 13, I wouldn't worry too much. Same box of primers?
Spaces after punctuation.
Click to expand...

good point,I just checked my load data,and that is what I'm using for a load,which is below max accorrding to hogdon site wich say's mv should be 3741 fps,,but then if you compare it to hornady manual,my load of 27.3 is over their max load of 26.7,but their load produces a mv of 3800 fps.I am pretty sure my chrony is working correcttly.
 
I can`t speak for you particular cartridge. However I have seen a batch of primers that were brittle and they were creating cookie cutter type pierced primers. No signs of pressure, velocity was right in line with all the other ammo fired. It was happing in all the rifles we were firing on the line that day. Same lot of factory ammo all being fired in factory guns. A quick call to the company and a lot a switch solved the issue.
 
I'm taking all your input folk's and thank you very much,I havent been to gunsmith yet to see if their is an issue with my firing pin,,but what I did try was shooting my full length resized brass handloads same load,just to see if neck sized was not chambering as snug as it should.Guess what shot two rounds off at a skunk the other night and no issues,BUT let a couple of rounds off tonight on a skunk( and wow the second shot flipped that criitter 3 feet in the air,at 30 yards,lol,,),I had a pierced primer,but that's what hanloading is all about,now I get to play and try to figure what's wrong,,MY thought is ,instead of pulling these rounds' and try a cci BR 4 primer,or reducing my load by 0.3gr,What about reducing my col by .003 to see if I can lessen pressure a little ??
 
I've seen two older mausers ,one a Swedish 96 and the other an Israeli 98 that pierced primers even with moderate loads .It was worn /sloppy firing pin holes.Not in your case but another reason this can happen.Did you per-chance work out loads with a said powder then buy more with a different lot number?Harold
 
well I thought I would seat the bullets .007 deeper to make a col of 2.260 to see if that would help by reducing pressure a bit,but when I heard the powder crunching (compressing )..it just didn't feel right,lol. So I pulled the remaining rounds and did 10 rounds up at 27.0gr of h4895,and will shoot them this weekend and hopefully they still group well and don't pierce primers,if they do I'm gonna try some factory hornady 40gr just to see if it's a firing pin problem..
 
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