Borchardt-Luger Controversy

unspellable · 08-20-2002, 09:25 AM

Different firearms operate in some what different ways, including the exact details of how they feed a cartridge into position.

Most submachine guns are blow backs and many are slam fired. That is, the firing pin is fixed to the face of the breech block and the impact of the closing breech fires the cartridge. Such guns are fired from an "open bolt" position. A design of this sort depends on using blow back operation rather than a locked breech so that the exact position of the breech block (To within thousandths of an inch.) is not critical when the cartridge fires. The feed path must accommodate the fix firing pin protruding from the breech face. The usual design headache with this type of firearm is finding a way to slow down the rate of fire while maintaining reliability.

In the Luger, the feed path is such that with the firing pin protruding from the face of the breech it would block the rim of a cartridge sliding up into position. This is a key point. There was an earlier discussion on this forum about the cartridge sliding up under the extractor rather than the extractor coming forward and riding over the rim. Retaining the firing pin also prevents slam fires.

The firing pins in many of those "other" pistols are restrained by a strong firing pin spring and possibly a firing pin block. The main spring is in the frame and drives the hammer with sufficient force to overcome the resistance of the firing pin spring. The Luger is striker fired and must have the main spring directly driving the striker or firing pin.

I have seen the same article Doubs mentions about the spring guide acting as a snubber. Like Doubs, I am a bit dubious. This is one of the questions on the agenda for my project. I will be rigging tell tales to determine just how far back the action goes and whether the spring guide actually does contact the frame or recoil spring link. Part of the motivation is to determine the proper range of cartridge impulse and recoil spring strength to obtain proper functioning without abusing the pistol.

08-20-2002, 09:25 AM	#31
unspellable User Join Date: Jun 2002 Location: Iowa Posts: 768 Thanks: 0 Thanked 19 Times in 11 Posts	Different firearms operate in some what different ways, including the exact details of how they feed a cartridge into position. Most submachine guns are blow backs and many are slam fired. That is, the firing pin is fixed to the face of the breech block and the impact of the closing breech fires the cartridge. Such guns are fired from an "open bolt" position. A design of this sort depends on using blow back operation rather than a locked breech so that the exact position of the breech block (To within thousandths of an inch.) is not critical when the cartridge fires. The feed path must accommodate the fix firing pin protruding from the breech face. The usual design headache with this type of firearm is finding a way to slow down the rate of fire while maintaining reliability. In the Luger, the feed path is such that with the firing pin protruding from the face of the breech it would block the rim of a cartridge sliding up into position. This is a key point. There was an earlier discussion on this forum about the cartridge sliding up under the extractor rather than the extractor coming forward and riding over the rim. Retaining the firing pin also prevents slam fires. The firing pins in many of those "other" pistols are restrained by a strong firing pin spring and possibly a firing pin block. The main spring is in the frame and drives the hammer with sufficient force to overcome the resistance of the firing pin spring. The Luger is striker fired and must have the main spring directly driving the striker or firing pin. I have seen the same article Doubs mentions about the spring guide acting as a snubber. Like Doubs, I am a bit dubious. This is one of the questions on the agenda for my project. I will be rigging tell tales to determine just how far back the action goes and whether the spring guide actually does contact the frame or recoil spring link. Part of the motivation is to determine the proper range of cartridge impulse and recoil spring strength to obtain proper functioning without abusing the pistol.