Piercing primers

[spencerhenry]

i am not claiming to be an expert about reloading, but i have loaded tens of thousands of rounds in numerous calibers. i have never heard nor seen any indication that not crimping a bullet would cause that issue. there is also NO reason to indicate that a crimped bullet would be seated deeper. seating depth while using a crimp is limited to where the cannelure is, but that does not mean that if uncrimped the bullet is seated shallower. almost none of the bullets i load for rifle calibers have a cannelure.

if you are piercing primers, there could be a few different issues. military ammo is known to have thicker primer cups, commercial may as well depending on the manufacturer, primers for reloading could have thinner cups. your firing pin could be "sharp" or could be protruding too far, switch out the pin, or the entire bolt from a gun that doesnt pierce the primer. do you have other signs of high pressure? check the case heads for expansion with a micrometer compared to the unfired round. if the rifle is over gassed, or the bolt is opening too soon, the more likely result is expanded case heads. does the headstamp have shiny spots, or is the rim bent from the extractor? those would be signs of the bolt opening under pressure. is the primer flattened or set back against the bolt face? that could mean high pressure.
first thing i would do is compare firing pins from the two different uppers, if you are using the same firing pin, then i would start looking at pressure problems. i have never had a primer pierce, but i have definitely loaded some maximum to slightly over maximum loads. does the loading manual where you got this load recommend a magnum or standard primer? it isnt a pistol primer right?

[MattR]

I forgot to mention the chamber is the Wylde chamber, I thought about the firing pin being sharp so I put a new one in it and same thing. My guess is that the carrier tilts as it cycles because there is a sign of wear on the buffer tube and hangs up just long enough to spike the pressure. I'm going to try a different tube and then go back to the GI and see what happens.

[CTN]

Here is some information from a very good black rifle smith that has a shop in Pueblo West.

http://www.68forums.com/forums/showthread.php?t=16256