recoil spring weights

[ernstus]

New to the forum and had a question. I just built a 9mm 1911. caspian race frame and sti slide. My question is what recoil spring would you recomend. Right now i'm running a #9 and it seems a little on the light. I'm using 125gr ld rn and loading them to minor power factor. The gun runs ok, it just doesn't always go completely to battery and I think the spring is the answer. There it is, so throw it on me.

thanks

[al503]

I use a 10 lb variable recoil and a 17 lb mainspring.

[luckylager]

Wouldn't hurt to try an 11 or 12 lb spring. Just make sure that the brass ejects at least a few feet away.

[CocoBolo]

The problem your describing is typical of new guns for two reasons. First reason is they are tight. With my 45 I had to run an 18lb spring to get reliably into battery. As the gun wore in I kept dropping the loads and the spring. After nearly 1000 rounds I'm running a 12# at 168 pf. I started at about 180pf.

The second reason is the bullets are too long. Yes especially if they are lead or moly coated bullets. Each bullet has its own profile and you need to make sure you have them the right length. Some times as little as -.005 can make a heck of a difference.

In your 9 bump it up to a 12# if that makes it run then let it break in well and then you could drop as low as 7#. I run a 7# in my infinity 9 mm for 120pf steel loads and a 9# for 130pf loads. Be sure to put the open end of the spring toward the muzzle end of the gun.

The powder you use can make some difference. Soft loads are N320, Clays, WST, TiteGroup the faster powders. I run 4.7gr of WST with a 124/125gr or 4.2 gr of TiteGroup with 124/125 gr jacketed bullets loaded out to 1.150. Flat nose bullets are a lot shorter I'm thinking they were 1.10 or there abouts been a while.

Edited December 10, 2009 by CocoBolo

[DWFAN]

I second the long bullet question. My Dan Wesson PM-9 has slight problems over 1.140 with a 147gr LFP. Check the bullet for rifling marks. The PM-9 came with a 10lb spring, and I run an 8lb now. I shoot 2.4gr clays or 3.0-3.2 gr Solo under the 147gr LFP.

(my bullet will have a different profile, but you should still check to see if the load length is the problem before respringing the gun)

[warpspeed]

I always have a box of Winchester Whitebox handy to check if is the ammo or something else.

I usually find it is something with the ammo. "once fired" mixed brass is usually the culprit. Especially in 9x19

[Aircooled6racer]

Hello: One day I went out with my 9mm single stack and decided to check recoil springs doing Bill Drills. I used a timer and some of my IDPA reloads using 147 grain Precision bullets. I ran about 300 rounds through the pistol using recoil springs from 8lbs to 18lbs My goal was accurate hits and lowest time to do so. I went up in spring rate and then down and back again. These were all Wolff brand recoil springs and all new. The best one for me was actually a 14lb spring. It grouped the best and had the lowest time but it did not feel the best. Using the clock helped alot since it doesn't lie or fool you I used a 18lb mainspring and the loads are 131PF. The pistol is a Kimber Eclipse 9mm/40. I need to do this test again using ISMI springs and a 17lb mainspring with 121 grain Montana Gold bullets. One thing you may need is a heavier spring since the pistol is new and also use lots of lube on the frame and slide. Hope this helps. Thanks, Eric

[hammerspring]

I have a 9mm colt that i made in too a cup gun. I am running 133 pf which is very accurate and i would like to keep. The gun runs about 98%, i am running a wolf 7# recoil spring with four coils cut off. Using a uncut 7# spring it runs about 60% . I can not find anything lighter, where do i go from here? Lighten the slide?

[goneracin]

I have a 9mm colt that i made in too a cup gun. I am running 133 pf which is very accurate and i would like to keep. The gun runs about 98%, i am running a wolf 7# recoil spring with four coils cut off. Using a uncut 7# spring it runs about 60% . I can not find anything lighter, where do i go from here? Lighten the slide?

have you tried the mainspring? my 9X19 was sporadic even with the 7# until i dropped the mainspring down to 16-17 lbs.

it wont fire for me at 15.

I also had to lighten my slide when I put a comp on it to get it to run right.

BTW, I run roughly 138 pf

[Bob DuBois]

On my STI Trojan 9mm minor with light bullets, 115 and 124 a 10lb spring runs good. With heavy 147 bullets I had to drop to a 9lb to get the slide to lock back every time. The gun has a little over 5,000 rounds through it now. Ammo loaded to 130 pf.

Yours being new will need at least a 10lb and maybe a 12lb to get it to run, several of the 1911 ESP shooters here run 12lb springs on broken in guns. If yours is tight you might have to go higher than a 12lb.

I use Wilson 10 round mags and cut two coils off the magazine springs. My gun likes oil and I use Mobil fully Synthetic 5W30, good stuff and a quart goes a long way.

The test done by Aircooled6racer is the best way to test which spring weight will work best for you. Pick up a selection and spend an afternoon tuning, it'll pay off.

[hammerspring]

I have not but will do so and see if that gives me 100%, Thanks for the info.

[TMC]

I use a 10# in my SV 9mm.

[DWFAN]

I have a 9mm colt that i made in too a cup gun. I am running 133 pf which is very accurate and i would like to keep. The gun runs about 98%, i am running a wolf 7# recoil spring with four coils cut off. Using a uncut 7# spring it runs about 60% . I can not find anything lighter, where do i go from here? Lighten the slide?

Does it have a comp ? Most cup guns Ive seen have slides lightened, with comps shooting the minor loads. I would suggest lightening the slide since you're already at a 7lb spring. Going with a lower mainspring, you may have to run only Federal primers. Some guys get away with a light MS, some guys dont.

[hammerspring]

I have a 9mm colt that i made in too a cup gun. I am running 133 pf which is very accurate and i would like to keep. The gun runs about 98%, i am running a wolf 7# recoil spring with four coils cut off. Using a uncut 7# spring it runs about 60% . I can not find anything lighter, where do i go from here? Lighten the slide?

have you tried the mainspring? my 9X19 was sporadic even with the 7# until i dropped the mainspring down to 16-17 lbs.

it wont fire for me at 15.

I also had to lighten my slide when I put a comp on it to get it to run right.

BTW, I run roughly 138 pf

I finally received my main springs, changed it out to a 17 lb with a new uncut 7lb recoil and new firing pin spring went to the range and put 100 rounds through it with out any problems. It does not seems to have any more recoil than before. I believe i will try it with a 8lb recoil spring just to see if it will run. Thanks for the advise.

[Jaxshooter]

When you cut coils off of the recoil spring you are not reducing the spring weight. The only reason to cut a recoil spring is to prevent spring bind. Another thing to look at is the firing pin stop. The more taper you have on the FP stop the easier the slide can go back to cock the hammer. Another thing to check is the magazine, is it over inserted in the gun etc?

[MichiganShootist]

I shoot a Springer 9 mm 1911. The factory spring weight that they recommend is 10-11 pounds for "standard" power loads.

I only shoot WWB and have never had a spring related issue.