to groove or not to groove

Vlim · 12-18-2009, 10:16 AM

Hi,

Although there is a chance that the grooves will prevent the pressure build up getting critical, the 'fix' was not to protect the firing pin from breaking, but the firing pin from getting stuck due to a buildup of dirt in the cavity of the breech block. The grooves (or flutes) help to push away any dirt.

The Finnish army had an interesting 'fix' for the prevention of damage from pierced primers. They drilled a tiny hole in the bottom of the breech block, creating a channel between the firing pin cavity and the outside. Any gases could vent through that hole, reducing damage.

Norme · 12-18-2009, 10:32 AM

I believe Vlim is correct, and that the grooves were to prevent the firing pin from binding due to a build up of powder residue.This probably became an issue with the introduction of steel cased ammunition which did not seal as well as brass. This fix was not new,as you can see from the cylinder pin from a Colt 1851 Navy. Regards, Norm

12-18-2009, 10:32 AM	#2
Norme Always A Lifetime Forum Patron Join Date: Jul 2009 Location: Colorado Posts: 2,417 Thanks: 226 Thanked 2,607 Times in 933 Posts	I believe Vlim is correct, and that the grooves were to prevent the firing pin from binding due to a build up of powder residue.This probably became an issue with the introduction of steel cased ammunition which did not seal as well as brass. This fix was not new,as you can see from the cylinder pin from a Colt 1851 Navy. Regards, Norm Attached Thumbnails

Thread Tools
Show Printable Version Email this Page
Display Modes
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode

12-18-2009, 10:16 AM	#1
Vlim Moderator Lifetime LugerForum Patron Join Date: Oct 2002 Location: Europe Posts: 5,053 Thanks: 1,036 Thanked 3,990 Times in 1,205 Posts	Hi, Although there is a chance that the grooves will prevent the pressure build up getting critical, the 'fix' was not to protect the firing pin from breaking, but the firing pin from getting stuck due to a buildup of dirt in the cavity of the breech block. The grooves (or flutes) help to push away any dirt. The Finnish army had an interesting 'fix' for the prevention of damage from pierced primers. They drilled a tiny hole in the bottom of the breech block, creating a channel between the firing pin cavity and the outside. Any gases could vent through that hole, reducing damage.