Wolff mainsprings

Stevie · 09-02-2002, 12:39 PM

I have a 1920 DWM luger which I bought a few years ago. As purchased this gun jammed alot, and rarely locked the toggle when empty. New mags and several brands/bullet wt. changes didnt help.
As I could find nothing else wrong with the gun,I did a little research and purchased a Wolff mainspring calibration set. The set included 36,38 and40lb springs + three new striker springs. I also got a pair of extra power mag. springs.
I installed the 36lb spring {quite a task} and presto! The gun works great. Extruded mag, standard mag, aftermarket mag,extra power spring mags,all brands/wts ammo Ihave tried work well.
So heres my question, is the 36lb spring too light for Rem.UMC 115gr. or Win.USA 115gr ammo. Am I going to beat this cool old gun to pieces, or should I try one of the heavier springs.
Any advice appreciated Stevie

Hugh · 09-02-2002, 01:21 PM

Stevie,

Lugers were built to operate with hotter ammo than todays American ammunition. That is why you had to go to a lighter spring to get reliable function. You can try the 38# spring, but that is probably equivalent to the original spring. If you get malfunctions, go back to the 36# one, be thankful and enjoy it, you are not going to hurt it. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Doubs · 09-02-2002, 02:14 PM

I agree with Hugh except that I wouldn't bother even trying the 38# spring. Unless the cases are being thrown an excessive distance upon ejection, it's a safe bet that the 36# spring is doing just fine. I'm a firm believer in the old axiom "If it ain't broke, don't fix it!"

Changing the recoil spring in a Luger can be a bear.... or it can be fairly easy if you know a few tricks. Some are detailed in the information to be found on the side panel of this forum. I can change one pretty quickly using only a couple of screwdrivers and a nut.

I capture the spring on the recoil spring bar's hook and compress it by screwing it down until it fits the compartment in the grip. I lay the frame (both grip panels off) flat on the table with the top part of the frame off of the table and against my body. The nut of proper size is laid on the table in the grip slot and against the cross piece that the recoil spring bar passes through. This keeps the top of the spring from slipping under the grip as it has a habit of doing if not supported. (It would be easy enough, I suppose, to fashion a piece of flat metal of the correct thickness to fill the entire slot and maybe even be secured in place using the grip screw. If one changed a lot of springs.) With a screwdriver tip of the proper size and shape, I push the recoil spring bar toward me and using my other hand and a small screwdriver I push the recoil spring bar hook over the recoil lever. Ease off the tension and you're finished.

Thor · 09-02-2002, 02:48 PM

I alson find the #36 spring works well with most US 9mm Luger ammo. I have to load a pretty warm hand load to make the #38 spring (supposed to be a factory new replacment) work right.

Stevie · 09-02-2002, 03:44 PM

Thanks for the advice guy's. I worried about tearing up the DWM so much, that I bought another luger to take the heat off of it. At least thats what Itold my wife. It's a 42 mauser. I've noticed that it is a lot stiffer feeling than the old DWM,a lot better shape,{my friends thought it was new} and just as accurate. I have not shot the 42 much, but it appears to be reliable even with its heavier feeling mainspring. Thank you Mother Russia for all the cheap luger's
best wishes Stevie

unspellable · 09-03-2002, 06:02 PM

The Wolffe 38 lbf spring is based on a spring Wolffe measured from a WWII vintage Mauser. If it was a factory spec spring it would be for a reasonably hot 9 mm load.

The only definite factory specs I have turned up so far are for the recoil spring in the DWM New Model chambered for 7.65 mm.

Free length: 3.346 +/- 0.0098 inches, 19 coils
Preloaded: 1.969 inches, 18.75 to 24.11 lbf
Loaded: 1.338 inches, 33.07 to 36.37 lbf

Fiocchi and Winchester 7.65 ammo are loaded too lightly to provide reliable functioning with this spring, hence the abundence of odd and cut springs that you find in Lugers. I advise against cutting any original spring on grounds you've altered the pistol and it will not have the correct preload force. Plus, you will want a standard spring to shoot handloads that are up to snuff. Lay it to one side and put in a replacement spring. I'm still trying to find a good source for replacement springs as the Wolffe springs are too stiff for the 7.65 mm chambering.

09-02-2002, 12:39 PM	#1
Stevie User Join Date: Aug 2002 Location: Ok. Posts: 212 Thanks: 0 Thanked 0 Times in 0 Posts	Wolff mainsprings I have a 1920 DWM luger which I bought a few years ago. As purchased this gun jammed alot, and rarely locked the toggle when empty. New mags and several brands/bullet wt. changes didnt help. As I could find nothing else wrong with the gun,I did a little research and purchased a Wolff mainspring calibration set. The set included 36,38 and40lb springs + three new striker springs. I also got a pair of extra power mag. springs. I installed the 36lb spring {quite a task} and presto! The gun works great. Extruded mag, standard mag, aftermarket mag,extra power spring mags,all brands/wts ammo Ihave tried work well. So heres my question, is the 36lb spring too light for Rem.UMC 115gr. or Win.USA 115gr ammo. Am I going to beat this cool old gun to pieces, or should I try one of the heavier springs. Any advice appreciated Stevie

09-02-2002, 01:21 PM	#2
Hugh RIP Join Date: Jun 2002 Location: Southeast Texas Swamp Posts: 2,460 Thanks: 2 Thanked 165 Times in 64 Posts	Stevie, Lugers were built to operate with hotter ammo than todays American ammunition. That is why you had to go to a lighter spring to get reliable function. You can try the 38# spring, but that is probably equivalent to the original spring. If you get malfunctions, go back to the 36# one, be thankful and enjoy it, you are not going to hurt it. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> __________________ *TRUMP FOR PREZ IN '20!*

09-02-2002, 02:48 PM	#4
Thor User Join Date: Jun 2002 Location: Rio Rancho, New Mexico Posts: 4,583 Thanks: 958 Thanked 970 Times in 276 Posts	I alson find the #36 spring works well with most US 9mm Luger ammo. I have to load a pretty warm hand load to make the #38 spring (supposed to be a factory new replacment) work right. __________________ Thor's Luger Clinic http://members.rennlist.com/lugerman/ Ted Green (Thor Yaller Boots) 725 Western Hills Dr SE, Rio Rancho, NM 87124 915-526-8925 Email thor340@aol.com ----------------------------------- John3:3 Jesus answered and said to him, "Most assuredly, I say to you, unless one is born again, he cannot see the kingdom of God."

09-02-2002, 02:14 PM	#3
Doubs User Join Date: Jun 2002 Location: Byron, Georgia Posts: 1,670 Thanks: 769 Thanked 1,611 Times in 525 Posts	I agree with Hugh except that I wouldn't bother even trying the 38# spring. Unless the cases are being thrown an excessive distance upon ejection, it's a safe bet that the 36# spring is doing just fine. I'm a firm believer in the old axiom "If it ain't broke, don't fix it!" Changing the recoil spring in a Luger can be a bear.... or it can be fairly easy if you know a few tricks. Some are detailed in the information to be found on the side panel of this forum. I can change one pretty quickly using only a couple of screwdrivers and a nut. I capture the spring on the recoil spring bar's hook and compress it by screwing it down until it fits the compartment in the grip. I lay the frame (both grip panels off) flat on the table with the top part of the frame off of the table and against my body. The nut of proper size is laid on the table in the grip slot and against the cross piece that the recoil spring bar passes through. This keeps the top of the spring from slipping under the grip as it has a habit of doing if not supported. (It would be easy enough, I suppose, to fashion a piece of flat metal of the correct thickness to fill the entire slot and maybe even be secured in place using the grip screw. If one changed a lot of springs.) With a screwdriver tip of the proper size and shape, I push the recoil spring bar toward me and using my other hand and a small screwdriver I push the recoil spring bar hook over the recoil lever. Ease off the tension and you're finished.

09-02-2002, 03:44 PM	#5
Stevie User Join Date: Aug 2002 Location: Ok. Posts: 212 Thanks: 0 Thanked 0 Times in 0 Posts	Thanks for the advice guy's. I worried about tearing up the DWM so much, that I bought another luger to take the heat off of it. At least thats what Itold my wife. It's a 42 mauser. I've noticed that it is a lot stiffer feeling than the old DWM,a lot better shape,{my friends thought it was new} and just as accurate. I have not shot the 42 much, but it appears to be reliable even with its heavier feeling mainspring. Thank you Mother Russia for all the cheap luger's best wishes Stevie

09-03-2002, 06:02 PM	#6
unspellable User Join Date: Jun 2002 Location: Iowa Posts: 768 Thanks: 0 Thanked 18 Times in 10 Posts	The Wolffe 38 lbf spring is based on a spring Wolffe measured from a WWII vintage Mauser. If it was a factory spec spring it would be for a reasonably hot 9 mm load. The only definite factory specs I have turned up so far are for the recoil spring in the DWM New Model chambered for 7.65 mm. Free length: 3.346 +/- 0.0098 inches, 19 coils Preloaded: 1.969 inches, 18.75 to 24.11 lbf Loaded: 1.338 inches, 33.07 to 36.37 lbf Fiocchi and Winchester 7.65 ammo are loaded too lightly to provide reliable functioning with this spring, hence the abundence of odd and cut springs that you find in Lugers. I advise against cutting any original spring on grounds you've altered the pistol and it will not have the correct preload force. Plus, you will want a standard spring to shoot handloads that are up to snuff. Lay it to one side and put in a replacement spring. I'm still trying to find a good source for replacement springs as the Wolffe springs are too stiff for the 7.65 mm chambering.