Gunboards Forums banner
1 - 7 of 7 Posts

·
Registered
Joined
·
22 Posts
Discussion Starter · #1 ·
So last night i was fidling around with my mk IV and i couldn't help myself I took a primed brass and set it off. I was curious as to where the pin would strike the primer and it did strike right in the center. When i extracted the case the primer was protruding enough for me to catch my finger nail on pretty well. So why did it do that and should i be worried about it when i am ready to shoot it?
Well thanks again
Levi
 

·
Platinum Bullet Member
Joined
·
4,612 Posts
Perfectly normal. When the primer fires, Newton's 3rd Law comes into effect and the primer is forced out of the pocket until it contacts the breechblock face. Normally, the consequent ignition of the main charge would force the case back against the block face in the same manner, thus reseating the primer. A protruding primer like you describe is a normal indication of a light, or in this case nonexistent, load.
 

·
Registered
Joined
·
25 Posts
It depends. Without actually seeing it, it is hard to say. A protruding primer could indicate that there may be more headspace than desirable especially in an older military gun. Check the rim thickness of your case against specs to rule that out. You may be able to get a button type headspace gage from one of the vendors listed on the sticky at the beginning of the forum.
 

·
Administrator
Joined
·
4,137 Posts
It depends. Without actually seeing it, it is hard to say. A protruding primer could indicate that there may be more headspace than desirable especially in an older military gun. Check the rim thickness of your case against specs to rule that out. You may be able to get a button type headspace gage from one of the vendors listed on the sticky at the beginning of the forum.
This is all wrong! Firing just a primer will back the primer out just as Jarhead75 says. Using a Modern Headspace gauge to "specs" won't work either. In fact .303 quages will not even go in a .303 Martini chamber. The Martini chambers were made far before the age of standardization, as much as 100 years before. The gauging standards when the guns were made was different than modern standards.

If the primer protrudes after firing a loaded cartridge then protruding primer means something.
 
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top