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saands · November 8, 2002, 12:37 PM

I imagine that someone will correct me if I am mistaken, but my understanding of a slamfire is that it is the firing of a round due to the firing pin striking the primer without the pull of the trigger (in a gun not designed to operate in this fashion ... think Sten). This can happen for at least two general reasons:
1. Many semi-auto weapons have free floating firing pins. this leads to the firing pin continuing to travel forward after the bolt closes ... normally the pin isn't travelleing nearly fast enough to actually fire the next round, but quite often it is travelling fast enough to leave a tiny ding on the primer. If you have the wrong firing pin (too heavy) or your weapon has a spring in front of the pin that is missing or if your primers are too soft (using small pistol primers 'cuz you ran out of small rifle primers?) then this can lead to the automatic detonation of subsequent rounds.
2. Your firing pin is stuck out! This can happen easily with rifles that have been stored in cosmoline for years and never received a thorough cleaning ... the SKS's seem to be good candidates for this failure as some people believe that they actually never require cleaning

Mine never did that, but mine are so clean that you could mince garlic with my bolts and not taste the difference in your fettucini. I think that a legal select fire rifle would be tons of fun, but the thought of one of my semi's going auto on me is too scary ... especially since it could start when letting the bolt fly forward to chamber the first round ... no trigger pull at all! I won't take chances there.

It is good to understand how your weapons function ... you might be surprised! As an engineer, the whole free-floating firing pin seems a little too close to the edge for me, but over the years the results seem to state that the design has some margin ... but you should know that it isn't bullet-proof. For that reason, I won't chamber a round in the SKS inside the house unless I am preparing to fire that round inside the house. My 1911, on the other hand, doesn't ding the primer at all, so that's a different deal.

I think I got it mostly right ... hope it helps
Saands

November 8, 2002, 12:37 PM	#9
saands Senior Member Join Date: November 14, 1999 Posts: 1,573	I imagine that someone will correct me if I am mistaken, but my understanding of a slamfire is that it is the firing of a round due to the firing pin striking the primer without the pull of the trigger (in a gun not designed to operate in this fashion ... think Sten). This can happen for at least two general reasons: 1. Many semi-auto weapons have free floating firing pins. this leads to the firing pin continuing to travel forward after the bolt closes ... normally the pin isn't travelleing nearly fast enough to actually fire the next round, but quite often it is travelling fast enough to leave a tiny ding on the primer. If you have the wrong firing pin (too heavy) or your weapon has a spring in front of the pin that is missing or if your primers are too soft (using small pistol primers 'cuz you ran out of small rifle primers?) then this can lead to the automatic detonation of subsequent rounds. 2. Your firing pin is stuck out! This can happen easily with rifles that have been stored in cosmoline for years and never received a thorough cleaning ... the SKS's seem to be good candidates for this failure as some people believe that they actually never require cleaning Mine never did that, but mine are so clean that you could mince garlic with my bolts and not taste the difference in your fettucini. I think that a legal select fire rifle would be tons of fun, but the thought of one of my semi's going auto on me is too scary ... especially since it could start when letting the bolt fly forward to chamber the first round ... no trigger pull at all! I won't take chances there. It is good to understand how your weapons function ... you might be surprised! As an engineer, the whole free-floating firing pin seems a little too close to the edge for me, but over the years the results seem to state that the design has some margin ... but you should know that it isn't bullet-proof. For that reason, I won't chamber a round in the SKS inside the house unless I am preparing to fire that round inside the house. My 1911, on the other hand, doesn't ding the primer at all, so that's a different deal. I think I got it mostly right ... hope it helps Saands