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Mainspring Question

1118 Views 18 Replies 10 Participants Last post by  oldcolt
Just wanted to know what poundage mainspring you reccommend for different loads. I have always shot 230 gr loads using an 18.5# mainspring but am unfamiliar with which poundage to select for lighter loads. Any help would be appreciated.

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Are you asking about the mainspring or recoil spring??
18.5 is a standard recoil spring..but the mainspring is in the housing in the grip and stock is usually a near a 21# with a 19# for light triggers.
If you are talking about the recoil springs, it really depends on how light a load you are talking..they come as light as 7 pounds.
In fact the factory recoil spring is 16#.

Ne Conjuge Nobiscum
Leonidas c 480 BC
The factory hammer spring is 23#. The recoil spring is 16#. These two springs work together during the recoil cycle. If you lighten the hammer spring you should increase the recoil spring weight. The 1911 was designed to function with 230 gr. ball ammo at about 830 fps.
Sorry about the confusion folks, these things happen when you think of one thing then write another. I am actually referring to the recoil spring poundage. My question is - Are there any recommendations as to when to decrease poundage for certain loads or is it mainly "trial and error". Would a 16# recoil spring give me a larger load variance? or Would the 230 gr loads be too hard on the gun over time with a 16# recoil spring in place? Sorry for the oversight.

I forgot to include that the gun came stock with an 18.5# recoil spring.

JMB designed the pistol for 230 grain FMJ ammo at 825 +/- 25 FPS with a 16# recoil spring. I don't think a steady diet of ammo that meets those specs should cause any problems. FWIW

Ne Conjuge Nobiscum
Leonidas c 480 BC
thanks Jim, I appreciate the info.

After a couple thousand, it should be replaced...


I Like The Shade Too!
And replace the firing pin spring too.
If your slide locks back on the last round with the 18.5#, that's the right spring for that load (23 Ball). I believe your original question was about using lighter loads. Start with a heavy spring, load one round and see if the slide locks back. If it does, you've found the right sping....if it doesn't, go to a lighter spring until it does lock back. You should always use the heaviest spring that will function the pistol properly because it'll keep from battering at the recoil points.
For Pistolwrench. Your comment tells me you may know something I need to know. I've been using this spring benchmark for 50 years and if there's something I need to be aware of, I'd sure appreciate your straightening me out.
This question comes up frequently, and there are always three or four different theories espoused. I would argue that JMB/Colt/Army Ord got it right, after 10-15 years of development, when they settled on 16# . . . Or did they? That is, they got the right spring; but is it 16#? Look in the archives for reference to an American Handgunner article, penned by Ed Brown, on the original/proper recoil spring rate.
For RickB. You're right, Mr. Browning and Army Ordnance knew what they were doing. And when I carried a 1911 that positively had to function because lives depended on it I had a 16# spring in it. But for smoothness of operation and longevity of parts, the 18.5 is the answer. I have probably rebuilt a thousand military 1911's that had been beat to death, but then we had access to any and all parts we needed and it didn't matter how well the pistol held up.
Don't know what else to say, except that a military 1911 is a far cry from a civilian one.

In a previous post you recommended using the "heaviest spring that would function the pistol properly".
In my experience with 45 Supers, I have found that hardball equivalent will run fine with even a 28lb. spring installed. Granted, the empties are not thrown very far, but with a firm grip, the slide will lock back.
I don't believe either of us would suggest using such a spring for normal loads, as the gun will be battered by the forward motion of the slide.
Your use of an 18.5lb. spring in a government model is just fine.
I just thought that using your benchmark of 'proper function' might lead someone to using a spring of unreasonable strength.
Personally, I use a Wolff 16.5lb variable in the gov't length, an 18lb. in the commanders and a 22lb. in the officers.
With modern metallurgy and a good barrel fit,
as well as a proper mainspring, battering is not an issue.
I'm wondering if these pistols that had "been beat to death" were WW2 vintage guns with soft slides, or just guns that may have seen well over a 100k rds., with little or no maintenence.
If you have the time, I'd love to hear specifics of the damage you found. 50 years of experience with 1911's is an awesome data base.

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Hi Chuck,
I do agree with your spring choices, except I still like the 18.5 for ball. The cases don't go into orbit and the recoil isn't as sharp. The only metal stressed by that spring is the slide stop, and they're pretty tough. I can't remember ever having seen one break....wear, yes, break, I just don't remember.
On the damage I found. Most of those pieces were WWII vintage, and many of them had the two-tone slides and many were either fully hardened or quite soft. All the other parts were pretty darn good...forged and hardened. The pistols had about every kind of injury you can imagine. From being used as hammers to firing with sand-plugged bores, to just worn-out from training/practice firing. Many had cracked frames, cracked slides usually the front edge of the ejection port, battered barrel recoil ledges (the area just under the hood), battered bottom barrel lugs, broken and/or rounded-off top lugs, both barrel and slide, cracked barrel links, broken extractors, loosened ejectors, broken and/or too short leaf springs (center leaf), and a bunch more. You name it and if it could be broken, it was. Lots of these pistols were match-conditioned and most of the work on them was just replacing barrels, bushings, trigger jobs and tightening the slide-to-frame fit. Of course replacing all springs on all pistols was routine, as well as replacing the disconnectors. I remember one bunch of pistols that had soft firing pins that would batter and then stick in the forward position in the firing pin stop. You can imagine the results of that.
I guess that'll do it. We've strayed a lot from the question of which spring for light loads, but what the heck, it's all educational for some of us. Regards. Bob
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What Main spring do you recomend when using a 16.5 variable recoil spring? would a 17 pound standard be almost equal to the 16.5 variable?

Well, I felt a call to Colt was in order and this is what they suggested - 18 lb recoil spring for 230 gr ball loads or equivalent. They also suggested using the 16 lb recoil spring for 165-200 gr loads.
I appreciate all of your comments on this matter as they have been helpful as well.

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