Quote:
Originally Posted by DavidJayUden
O:
The deep cuts near the top of the firing pin in the photo are what we refer to as fluting. I believe that this was a later addition to Lugers so in the event of a pierced primer the sudden infusion of hot gasses would have an escape path to bleed off thru rather than forcing the entire firing pin toward the rear.
Certainly a well-marked gun and you have done a good job on the photos.
dju
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This just not correct and is one of those myths that keeps on giving because it sounds logical: but, there is nowhere for the "gas" to escape from the fluting to.
If one just looks at the relation of the grooves/flutes to any possible escape point, one sees that they do not reach any.
The grooves are there to allow any dirt/powder/oil debris a place to live without rendering the striker immobile.
If anything, the grooves add more area for the gas pressure to push against, and we know that the force= area x pressure.
The Finns added an approx. 3/32" escape hole in the bottom of the breech block to address gas from a pierced primer; just at the forward most reach of the striker, the escape hole shown below. This hole allows an immediate and direct escape for excess gas, but not without the potential of damaging the magazine, and grips- which is the next area the gas escapes to if vented from the hole shown.
The fluting was added according to an Army directive in 1930 to be completed by 1931 and was practiced by armorers and repair depots; the fluting also applied to deliveries of New production(BKIW and later Mauser). The actual document is found in the three volume Goertz and Sturgess books,p. 1116. The numbering of the rear toggle pin was ordered in 1932, found on p-1120(Green edition).