Mainsprings revisited!

unspellable · 08-28-2007, 04:15 PM

GT, I sent Sieger the drawings for the original DWM springs.

Cutting coils reduces preload which is really a no no. The preload is critical to the last part of closing the action. The Luger WILL fire when not fully locked. I've demonstrated this with empty primed cases. Having this happen with a fully loade cartrdige doesn't bear thinking about.

For the 9 mm, the stock springs are the way to go. They like standard loads and assuming you have a good magazine, etc. the OAL of the cartridge is the problem area.

The 7.65 spring is a bit softer than the 9 mm spring. Here the problem is that today's store bought ammo IS underloaded. The ideal spring for this wimpy ammo would have the stock preload but less compressed load. The ideal for the individual pistol is when the the lip at the rear most point of the toggle will just consistantly crease a piece of tape on the rear of the frame.

An often misunderstood point is that the spring has almost no influence on the upper's recoil speed. It's first job is to bring the upper to a near stop by the time it hits the rear travel limit.

As Georg said, "The springs have to be right!"

08-28-2007, 04:15 PM	#6
unspellable User Join Date: Jun 2002 Location: Iowa Posts: 769 Thanks: 0 Thanked 20 Times in 12 Posts	GT, I sent Sieger the drawings for the original DWM springs. Cutting coils reduces preload which is really a no no. The preload is critical to the last part of closing the action. The Luger WILL fire when not fully locked. I've demonstrated this with empty primed cases. Having this happen with a fully loade cartrdige doesn't bear thinking about. For the 9 mm, the stock springs are the way to go. They like standard loads and assuming you have a good magazine, etc. the OAL of the cartridge is the problem area. The 7.65 spring is a bit softer than the 9 mm spring. Here the problem is that today's store bought ammo IS underloaded. The ideal spring for this wimpy ammo would have the stock preload but less compressed load. The ideal for the individual pistol is when the the lip at the rear most point of the toggle will just consistantly crease a piece of tape on the rear of the frame. An often misunderstood point is that the spring has almost no influence on the upper's recoil speed. It's first job is to bring the upper to a near stop by the time it hits the rear travel limit. As Georg said, "The springs have to be right!"