Primer piercing issue

[trotterlg]

After months sitting around I finally shot the 30 Carbine project.  I had picked up a box of Aguila rounds and had noticed that they are a full .010 shorter in the chamber than the Remington barss was.  Because I had chambered the barrel for the Remington brass and set the headspace to about .0005 I wasn't worried with .011, a little on the loose side but not anything to be stressed about.  Since I had shot the last stubbing project I have changed the hammer because I broke it tapping it for an extension, other than that it is the same receiver setup.  Fireing pin extension with the trigger pulled back is .048, and if I hold forward the transfer bar all the way the pin goes out to .070.  The hammer stop depth on both hammers is the same at .153.  Out of 20 rounds about 1 in three pierced the primer, not a lot, but they made a little hole and soot in the primer dent.  Do you think this is because of soft primers allowing the intertia of the fireing pin to pierce them with the .070 travel or should I take a few thousanths off the pin.  For sure I will not shoot the Aguila rounds again, but would like to do any fix before I go to the range with different ammo.  The barrel shot really well, I got a couple of 1 inch 3 shot groups with two touching so am pleased with the accuracy.  Larry

[LaOtto222]

How deep were the dents in the Remington brass? Before I modified the firing pin, I would make sure your dents are plenty deep enough in the tougher primers. It looks like the firing pin is just going in too far and fracturing the metal in the primer (the hole looks like a tear), but it may not do that with a tougher (thicker) primer.

[Roudy]

You didn't say if you intend to reload your own ammunition.  If you do reload then you might try small rifle primers, perhaps CCI brand.  Ive read that CCI tends to be a harder primer than Winchester or Federal and that has also been my experience.

Nice groupings!

Roudy

[edgemark]

If you do not full length re-size this ammo, it is now fire-formed to this chamber.
Reload and see if you still pierce primers, I suspect that it will not. I suspect that when you pull the trigger the cartridge is pushed forward the additional 0.011, but upon ignition it is pushed rearward and the firing pin is sticking out 0.011 longer than normal.

You should check the brass for a pressure ring near the head. If there is a thinning then chuck those cartridges and on fresh brass use a low load to form the brass. This brass will not fit a standard chamber once fire-formed.

edge

[Ireload2]

I would suspect the Aquila ammo first. Try some handloads with your favorite primer and I suspect your problem will go away.
I have have very light loads pierce primers with one brand and all the piercing stopped just by changing brands.
I think the material was just too hard to stretch when the firing pin hit it.

[trotterlg]

I am kind of leaning towards an ammo problem, I have had no problems until I shot the Aguila, not with this barrel, but with the same receiver, and this barrel has even less headspace than the last one.  I will try another batch at the range this weekend if I get time, I bet it will work.  Larry