LugerForum Discussion Forums - View Single Post - Borchardt-Luger Controversy

Doubs · 08-21-2002, 06:31 PM

[quote]Originally posted by unspellable:
<strong>Different firearms operate in some what different ways, including the exact details of how they feed a cartridge into position.

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.</strong><hr></blockquote>

The breechface of the Luger is recessed and encloses the rim of the cartridge. The cartridge base, therefore, cannot simply slide up the face of the breech and into position for firing. When the next cartridge is stripped from the lips of the magazine, it is being pushed upward by the ramp in front and forward by the lower part of the breechblock. When the bullet comes in contact - forcefully - with the chamber face, there is a mechanical "jump" of the cartridge upward. At the same time, the breech is still pushing forward on the cartridge and forces the nose of the bullet, as it jumps upward, into the chamber. The chamber centers the cartridge and in the final movement of the toggle train into battery, the extractor rides up and over the rim as the base of the cartridge seats in the recess of the breechface. Not until the final few thousands of an inch does the possibility exist for the firing pin to contact the primer. By this point in the feeding sequence, the sear would have engaged the firing pin and retracted it so that no contact would be possible between the pin and the primer... even if the hook wasn't part of the design.

Unlike the 1911 design that has a "controlled feed" - the rim slips under the extractor as it rides upward out of the magazine and is held against the breechface right into the chamber - the Luger does not control the feed of the cartridge and the extractor doesn't engage the rim until the very end. (If you want to break a 1911 extractor, drop a cartridge into the chamber and let the slide go forward. Unless specially modified to do so, the 1911 extractor does not ride over the rim to engage.)

While "inertia" or "rebounding" type firing pins do have a spring in front of them that must be overcome by the hammer, the VZ-52 and other Soviet Bloc designs have no spring on either end of the firing pin. The new cartridge primer pushes the pin back into firing position. The Makarov and the later SKS carbines come immediately to mind.

The design of the Luger firing mechanism, borrowing heavily on the Borchardt design, does several things to the firing pin assembly during recoil. We could discuss for years which is the "most" important or which is truly the "primary" reason for the design being as it is. All of the things it does are important to proper functioning and we'll both still have the same opinions. This has been an educational thread and I've learned a lot from it.

08-21-2002, 06:31 PM	#66
Doubs User Join Date: Jun 2002 Location: Byron, Georgia Posts: 1,736 Thanks: 819 Thanked 1,769 Times in 586 Posts	[quote]Originally posted by unspellable: <strong>Different firearms operate in some what different ways, including the exact details of how they feed a cartridge into position. 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.</strong><hr></blockquote> The breechface of the Luger is recessed and encloses the rim of the cartridge. The cartridge base, therefore, cannot simply slide up the face of the breech and into position for firing. When the next cartridge is stripped from the lips of the magazine, it is being pushed upward by the ramp in front and forward by the lower part of the breechblock. When the bullet comes in contact - forcefully - with the chamber face, there is a mechanical "jump" of the cartridge upward. At the same time, the breech is still pushing forward on the cartridge and forces the nose of the bullet, as it jumps upward, into the chamber. The chamber centers the cartridge and in the final movement of the toggle train into battery, the extractor rides up and over the rim as the base of the cartridge seats in the recess of the breechface. Not until the final few thousands of an inch does the possibility exist for the firing pin to contact the primer. By this point in the feeding sequence, the sear would have engaged the firing pin and retracted it so that no contact would be possible between the pin and the primer... even if the hook wasn't part of the design. Unlike the 1911 design that has a "controlled feed" - the rim slips under the extractor as it rides upward out of the magazine and is held against the breechface right into the chamber - the Luger does not control the feed of the cartridge and the extractor doesn't engage the rim until the very end. (If you want to break a 1911 extractor, drop a cartridge into the chamber and let the slide go forward. Unless specially modified to do so, the 1911 extractor does not ride over the rim to engage.) While "inertia" or "rebounding" type firing pins do have a spring in front of them that must be overcome by the hammer, the VZ-52 and other Soviet Bloc designs have no spring on either end of the firing pin. The new cartridge primer pushes the pin back into firing position. The Makarov and the later SKS carbines come immediately to mind. The design of the Luger firing mechanism, borrowing heavily on the Borchardt design, does several things to the firing pin assembly during recoil. We could discuss for years which is the "most" important or which is truly the "primary" reason for the design being as it is. All of the things it does are important to proper functioning and we'll both still have the same opinions. This has been an educational thread and I've learned a lot from it.