Quote Originally Posted by Parashooter View Post
It's not just the rimmed case that helps prevent gas reaching the firer. Unlike Mauser types, the Lee, Kragicon, and others have no left lug raceway serving as a gas conduit from breech toward eyeball. Consequently, gas from a failed case is vented only at the front of the receiver. Here's a demonstration -

This case had been reloaded with heavy loads enough times so it was stretched near breaking.

https://www.milsurps.com/images/impo.../117z9ck-1.jpg

I loaded it with a 180-grain bullet and 40 grains of 4895 - a reasonably stiff charge about 2 grains under "maximum" - and fired it in a much-abused Savage No.4 with a clean sheet of typing paper wrapped around the receiver.

https://www.milsurps.com/images/impo.../29fw5ft-1.jpg

When I opened the bolt, the separated head extracted. (The front piece of the case fell out when I turned the rifle muzzle-up.)

https://www.milsurps.com/images/impo.../11ayg6q-1.jpg

The sooty paper shows where some gas escaped. No rips or holes, just a little soot - and only where the bolt head meets the receiver ring. Had I been shooting from the shoulder and wearing glasses, I probably wouldn't have felt the leak at all.
Having said that, I've seen 2 people have their glasses shatter after the striker came back with enough force to hit their glasses lense.

Both incidents occurred with No4 rifles.

It's not a pleasant thing to pick glass fragments out of a friend's eye.