View Full Version : Rem. 721

March 19, 2010, 11:53 PM
How far should the firing pin protrude on my Rem 722?It was a 222 rem,changed to 17 rem.It pierces primers quite a bit.like every 4 or 5 rds it will pierce one.Factory loads and hand loads both.Also,a smith put a lighter weight spring in the bolt,he thought the one that was in there was too tight.

March 20, 2010, 01:47 AM
IIRC, firing pin protrusion should be .055"

March 20, 2010, 11:37 AM
Thank you Scorch.

March 20, 2010, 09:42 PM
One other question,do you know what the bolt face depth is supposed to be?I think my bolt face could be worn too much,that and the fp worn to .023 protrusion,might be my whole trouble with this rifle.

James K
March 20, 2010, 10:52 PM
Whoa, guys. Excess firing pin protrusion does NOT cause "pierced" primers. Unless the firing pin is needle sharp, no firing pin spring that a human can cock will drive through a primer.

The usual cause of blown out (not "pierced") primers is a weak firing pin spring that won't support the primer against the internal pressure, resulting in the primer forcing the firing pin back and a small disc of the primer blowing out into the firing pin hole in the bolt. If those discs build up inside the bolt, they will eventually block the firing pin and result in misfires.