[JohnC]

Yes, there is a length difference. The ILS spring is shorter. I used a regular 19lb mainspring and then trimmed it to the length of the ILS spring. That kept the ILS operational and made a difference on the trigger. I put about 5000 rds through the gun that way and never had a problem.

 

[deezulsmoke]

The easiest thing to do is replace the ILS parts with standard parts. Then you can use whatever power mainspring you want. I have experimented with many and have come to the conclusion that the best combo of springs for me for reliable ignition and clean round stripping is a 18# mainspring and 18.5# recoil spring.

Deez.

 

[Chuck S]

John's solution will preserve the ILS. My add-on may sound complex, but read it over anyway.

The issue here is the compressed length of a standard mainspring is too long to fit in the housing when the pistol is cocked. It's not the free length that's important, it's the compressed.

Mic the SA ILS spring coils, count them, and determine the compressed length. Do the same with your candidate standard M1911 mainspring and cut to length. If the coils are the same diameter it'll be fairly easy, just match the coil count. The coils should not botton out with the pistol is cocked. (I'm sure there's a technical term for this, but darned if I can remember it right now.)

-- Chuck

 

[WhyteP38]

Interesting replies; thanks.

Any suggestions of a good source of a mainspring? Midway? Brownell's? Other?

 

[steveracer]

Wolff has springs for your gun.

Wolff makes ILS springs to lighten trigger pull and retain ILS. www.Gunsprings.com is the website. Look for SA stuff.