springing 9mm and 38 super 1911s

[1911_Hardball]

One factor often overlooked is the radius of the firing pin stop. The larger the radius the easier the slide can overcome the resistance of the mainspring due to the contact point being higher on the hammer.
My STI 5" in 9mm was not 100% reliable. Its firing pin stop matched the radius of about any .45 1911 I've ever seen. The one in my Ruger SR1911 9mm had a noticeably larger radius. The STI cycled fine with the Ruger stop in it so a few minutes with the STI stop and a couple different grit stones resolved the issue without messing with any springs.

 

[tipoc]

From Wolff Gunsprings:

COLT 1911 FACTORY RECOIL SPRING NOTES
1. Factory rating for super .38 & 9mm is 14 Lbs.
2. Factory rating in .40 S&W is 19 Lbs.

Colt 1911, 1911A1, 1991, Government, MKIV, Gold Cup, & Commander in .45 ACP , Super .38/9mm calibers and Delta Elite 10mm.

Hammer springs are available in a variety of weights to allow adjustment of the trigger/let-off to individual needs. Hammer spring paks are recommended when exact poundage desired in unknown and offer a savings over individually purchased springs.

Reduced Power...: 15, 16, 17, 18, 19, 20 & 21 Lb.
Factory Standard : 23 Lb.
Extra Power........: 25, 26, 28, 30 & 34 Lb.

https://www.gunsprings.com/COLT/1911 GOV'T PISTOL/cID1/mID1/dID1#2

The springs for Kimber and 1911 recoil springs and hammer springs are identical to Colt's.

tipoc

 

[rc]

I fired my springfield again and only changed the recoil spring to a 9 pound rated one I had. My buddy said springfield uses 8.5. I had no misfires and the slide only failed to go into battery only a couple of times. One failure with mecgar 10 shot front dimpled magazine was magazine related with the follower hanging up inside and I could not get it to tap up to the top even after several tries. Trigger pull is still a bit heavy so I will order a new leaf spring that should take down the spring pressure on the trigger and disconnect a bit.

I also fired my switch barrel kimber and it's starting to run pretty well with both barrels with just a couple of slide bumps to finish seating the cartridge in over 100 rounds. The only problem with a buffer installed is that it was sometimes locking open with rounds in the magazine in 38 super. Strange....

 

[Aguila Blanca]

rc:

Respectfully, I again suggest that the reason your trigger feels heavy is that 28-pound hammer spring that Springfield uses. Aside from spring weight, the spring itself is different. You should be using a conventional hammer spring if you have changed out the mainspring housing and the mainspring caps and MSH pin retainer.

https://www.gunsprings.com/SPRINGFIELD/1911A1 SERIES/cID1/mID60/dID267

I also think that a 9-pound recoil spring is too light. Please note this, from the top of the page to which I linked:

Springfield 1911 Series pistols use the same springs as Colt 1911 Series Pistols with the exception of the hammer springs in some instances. Please see ILS hammer spring note below.

So, if we go to Colt, we find that in a full-size (5-inch) 9mm pistol the factory recoil spring is 14 pounds (which we've told you before). For a 9mm Commander length pistol in 9mm, the factory recoil spring is 16 pounds.

https://www.gunsprings.com/COLT/1911 GOV'T PISTOL/cID1/mID1/dID1
https://www.gunsprings.com/COLT/COMMANDER SERIES PISTOL/cID1/mID1/dID2

I don't know where your friend got the notion that Springfield 1911 use an 8.5-pound recoil spring. I have never heard or read that, and it makes no sense whatsoever.

Lastly, sear springs are rarely drop-ins. If you buy a Colt sear spring, you can drop it into most Colts and get about a 6-pound trigger. For other makes of pistol, or if you want a lighter trigger than 6 pounds, you'll need to learn how to tune a sear spring.

 

[Hammerhead]

SA has to use a light recoil spring because of the stupid lock.
I agree, you're going to struggle until you get a normal MSH setup.
Then you can use stronger recoil spring which will eliminate the failures to return to battery.

 

[Aguila Blanca]

rc is running a conventional mainspring housing. But he's still using the OEM Springfield hammer spring which, in addition to be a 28-pound spring, is a different length thana normal 1911 hammer spring.

 

[rc]

Can someone recommend a standard mainspring that will still work with the titanium springfield factory firing pin for reliable ignition? The gun is running pretty well now but I'm not sure if I trust it with a large variety of ammo like I do with a CZ 75. The springfield factory mainspring fit ok with the regular mainspring parts but it was hard to get it together due to the spring weight! As has been stated, I'm limited to lighter recoil springs by the heavy main spring that is needed to have a drop safe pistol with the titanium firing pin. There is a lot to be said for the improved series 80 systems Kimber and Colt are using for reliable drop safe performance. I agree a change in mainspring may help reduce trigger pull but there are lighter trigger/sear/grip leaf springs available.

 

[Aguila Blanca]

I believe most people find that a standard 23-pound mainspring works fine with the titanium firing pin. Try that -- if it doesn't work, move up to 25 pounds.

Kimber doesn't use a Series 80 firing pin block. They use a variation of the older Swartz firing pin safety that Colt used before WW2 and never used after the war. The Series 80 system is unlocked by the trigger. The Swartz is unlocked by depressing the grip safety.