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Wolf Recoil Springs For 1928, M1, 1921?


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#1 The Moor

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Posted 23 February 2004 - 10:04 AM

Got a tired recoil spring in a model 1928A1. The spring is 10 1/8" in length. I have an original issue (?) spring that is 11 1/2" in length (I thought the original issue springs were supposed to be 10 1/2 ") and a new Wolfe spring that is 11 3/4" in length. Which would be better to use in the 1928A1?

Also, has anyone used these Wolfe replacement springs in a M1 Thompson or the Wolfe 21 spring in a M1921?

All of the Wolfe springs seem pretty stiff and seems to me would make the cyclic rate faster. Or am I incorrect and they will do the reverse and make the cyclic rate slower?

Rob
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#2 PK.

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Posted 23 February 2004 - 10:45 AM

I just answered an e mail inquiry regarding this subject; I offer the test of that response here.

“TM9-1215 (3/1/42) says the free length should be 10 +.25" for inspection. I understand that another manual (which I don't have) shows a different number (supposedly longer). The guy in the field would have no interest in or use for further specifications, but as we both know, free length is only one of several important parameters. After examining several different springs of known origin (or at least a high probability of known), this is what I have observed: GI springs go 11.25" - 11.50" free length with 69-70 active coils, open ends. Wolff; 11.75", 67 active coils and closed ends, Whittenberger; 11", 72 active coils, closed ends. All are made from .042 wire and have a outside diameter of .385- .392, the Wolff being largest. I have used the military and Wolff with good results. I just received the Whittenberger the other day and will have to examine the effect of the extra coils, but good results have been reported by others. The Wolff seems to be a bit more aggressive than the GI due to the extra length and modern wire (I assume) and care needs be taken when installing it to avoid kinks, but not much more than usual.”

The M1 and ’28 models use the same spring. You will likely see an increase in cyclic rate with the new spring, but not much.

I have measured and used the Wolff ‘21 springs and find them compatible with the Colt springs I have examined.

FWIW

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#3 john

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Posted 23 February 2004 - 05:34 PM

I bought a couple springs from Sarco last year.....cut them down to 10.25" and they function flawlessly.
I do like Wolff springs, but why bother?

john
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#4 The Moor

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Posted 23 February 2004 - 06:50 PM

Thanks fellows. I'll try to get a few of those NOS springs from Sarco and then try the GI springs versus the Wolff. Want to try to keep the cyclic rate about where a 28A1 is supposed to be. With the weak spring that is in the gun it cycles about as fast as my 21.
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#5 Chopper28

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Posted 23 February 2004 - 07:53 PM

The Whitenberger springs are by far the best deal, $2.00 each, and work perfectly in my gun. Glen works for GM and had them designed using GM's CAD. I have seen GI springs from Sarco and others that vary in lenght by as much as one inch. Looks like they took a stock lenght of spring and snipped them off with wire cutters without a great deal of precision or accuracy. Just my .02
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#6 Chopper28

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Posted 24 February 2004 - 02:39 PM

PhilOhio,
I been dealing with Sarco for over 25 years. I've had both good and bad experiences with them. Overall I would agree that they do try to please and will make right any errors or unacceptable parts. I bought recoil springs from them that were of varying lenghts and some were rusted. The ones I got from Glen are brand new, less expensive, quick service and they work. I shoot my gun all the time. No problems. Go to Sarco's table at Knob Creek and take a look at some of the stuff they put out, if you can dig through all the crud that is usually on their parts. They have a large inventory but some times their service is lacking and the parts can be subpar. Sooner or later they may be the only place to get TSMG parts until then I will shop around. Just my .02
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#7 The Moor

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Posted 24 February 2004 - 03:21 PM

Hey Phil, great to know that this is one battle that we can't lose. I would hate to have to change my name and flee the country again. wink.gif
Ordered a bunch of the 28/M1 recoil springs from Sarco today. I've done a bunch of business with them over the years as well and am glad they are there. Can't imagine not having Sarco around. Have always enjoyed their ads in Shotgun News and would love to take a tour of the place (shopping tour).
If I can find out how to order the Whitenberger springs, I would like to get one or two of those as well and compare them all. However, I am most interested in having the Thompson function as it was originally issued and to me the GI springs, in NOS condition, are the way to go.

MacGregor
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