LugerForum Discussion Forums - View Single Post - Recoil springs

unspellable · 11-26-2002, 01:26 PM

Whether or not the action closes after being gently lowered onto the sear is not a valid test. It depends very much on the individual pistol. I have several in excellent working order and the results of this test are about 50/50 without much correlation with anything.

DWM factory specs for the recoil spring in a new model Luger chambered for 7.65 with barrel length between 98 mm and 150 mm are:

Outside diameter:
Min 9.90 mm or 0.38976 in
Nom 10.00 mm or 0.39370 in
Max 10.00 mm or 0.39370 in

Wire diameter:
Nom 1.40 mm or 0.05512 in

Free length:
Min: 82.50 mm or 3.24803 in
Nom: 85.00 mm or 3.34646 in
Max: 87.50 mm or 3.44488 in

Preloaded length:
Nom: 50.00 mm or 1.96850 in

Loaded length:
Nom: 34.00 mm or 1.33858 in

Preload force:
7-9 kg (sic) or 15.43 - 19.84 lbf

Loaded force:
15-16.5 kg (sic) or 33.07 - 36.38 lbf

This spring may work in some Lugers with Winchester 30 Luger ammo which is loaded somewhat lighter than the DWM load from the 1920's. The Winchester ammo will not reliably cycle my Ruger or any of three vinatge Lugers until I put a lighter spring in.

You will probably need a lighter spring for Fiocchi ammo which is loaded lighter than the Winchester. It will cycle my Interarms but fails to cycle my Ruger or any of three vintage Lugers.

If you have to cut a spring, DO NOT cut the one in the gun, besides messing up a possible original, it will result in too light a preload. The Wolff springs are over length and so lend themselves better to a little trimming.

Trim the spring a little at a time until the hold open works reliably. Put a gum wrapper against the frame under the rear toggle link extension. If the toggle extension taps it without really mashing it, you are in the right place.

Beware too light a spring failing to close the action all the way. A Luger WILL FIRE with the action almost closed but NOT LOCKED. The results do not bear thinking about.

Also, beware the spring you find in the gun to begin with. Many of them are not originals and you are liable to find anything from A to Z.

I will have more data on recoil springs at a later date.

11-26-2002, 01:26 PM	#6
unspellable User Join Date: Jun 2002 Location: Iowa Posts: 768 Thanks: 0 Thanked 19 Times in 11 Posts	Whether or not the action closes after being gently lowered onto the sear is not a valid test. It depends very much on the individual pistol. I have several in excellent working order and the results of this test are about 50/50 without much correlation with anything. DWM factory specs for the recoil spring in a new model Luger chambered for 7.65 with barrel length between 98 mm and 150 mm are: Outside diameter: Min 9.90 mm or 0.38976 in Nom 10.00 mm or 0.39370 in Max 10.00 mm or 0.39370 in Wire diameter: Nom 1.40 mm or 0.05512 in Free length: Min: 82.50 mm or 3.24803 in Nom: 85.00 mm or 3.34646 in Max: 87.50 mm or 3.44488 in Preloaded length: Nom: 50.00 mm or 1.96850 in Loaded length: Nom: 34.00 mm or 1.33858 in Preload force: 7-9 kg (sic) or 15.43 - 19.84 lbf Loaded force: 15-16.5 kg (sic) or 33.07 - 36.38 lbf This spring may work in some Lugers with Winchester 30 Luger ammo which is loaded somewhat lighter than the DWM load from the 1920's. The Winchester ammo will not reliably cycle my Ruger or any of three vinatge Lugers until I put a lighter spring in. You will probably need a lighter spring for Fiocchi ammo which is loaded lighter than the Winchester. It will cycle my Interarms but fails to cycle my Ruger or any of three vintage Lugers. If you have to cut a spring, DO NOT cut the one in the gun, besides messing up a possible original, it will result in too light a preload. The Wolff springs are over length and so lend themselves better to a little trimming. Trim the spring a little at a time until the hold open works reliably. Put a gum wrapper against the frame under the rear toggle link extension. If the toggle extension taps it without really mashing it, you are in the right place. Beware too light a spring failing to close the action all the way. A Luger WILL FIRE with the action almost closed but NOT LOCKED. The results do not bear thinking about. Also, beware the spring you find in the gun to begin with. Many of them are not originals and you are liable to find anything from A to Z. I will have more data on recoil springs at a later date.