Firing pin bushing

[Suicycle]

I cannot fully understand how bushing the pin will keep you from blowing primers. Are pierced primers not a high pressure sign? If so why would bushing the pin allow you to shoot them or even hotter? Man I am lost bigger than ...........well you know. Talk me through it here.

 

[jb1000br]

Bushing the pin fills in the space,tolerance) between the Fpin and the hole it goes thru in the boltface.

This closes the gap and inhibits blanking of the primers by supporting them completely. they are no longer unsupported around the edges of the FP.

also, yes, it allows use at increased pressure

you are still operating at safe pressures, and the brass can take it, so why not.

YMMV,
JB

 

[Dave]

A smaller diameter pin will exhibit less area on which the pressure can act. But I believe that the blanking most of us experience is caused by short-fall strikers being forced back by combustion pressure, permitting the already indented primer to reverse direction and break. I have an M17 which blanks 30% of primers when I use a close fitting titanium striker in conjunction with a stronger spring and a short fall. However this blanking problem is totally eliminated by switching to a heavy full-fall ill-fitting military striker.
Dave.