[Brian D.]

Howdy, as you like to say. I was reading something interesting on one of these gunboards recently about Springfield A's newer 1911s, with the ILS thingy. They use a heavier mainspring than normal, and supposedly this has the same helpful effect on trigger pull as the ol' "boosting the trigger" trick. Think that's so? I have one of their "Champion" models with this gizmo, and was thinking that at 1,000 rds or so--which is coming up soon--I'd yank the ILS-equipped mainspring and put in a lighter (normal) one. Whattya think? BTW the trigger's pretty good as she sits now--4lbs or a hair less I'd say...'n' crispy to boot.:cool:

[1911Tuner]

Howdy Brian,

The ILS mainspring is heavier than a standard spring...but not by a lot.
From what I can gather, it's in the neighborhood of about 28 pounds,
so it wouldn't have quite the same effect as boosting. but...as I've
often said...EVERYthing means SOMEthing...so it would tend to wear in
the hammer/sear engagement a little quicker than if it had a 23-pound mainspring.

One thing to keep in mind is that the mainspring has a very real effect on slide speed in recoil. Going to a lighter standard mainspring is going to
speed things up a bit. Since I haven't had the opportunity as yet to
have a look at an ILS-equipped Springer, I don't know what the recoil
spring load rating is...but I'm betting on about 14 pounds in the 5-inch pistol...and I don't have a clue in the Champion If so, going to a 23-pound mainspring MAY require upping to a heavier recoil spring, and POSSIBLY a Wolff magazine spring to keep up with the faster slide speed on the feeding stroke brought on by the heavier recoil spring. Every change
has an effect on other things. No way around it.

The chopped-slide 1911-pattern pistols are different animals, and some come with their own unique set of quirks. If you change out the ILS system, and run into function issues, change one thing at a time until
you hit the pistol's sweet spot.

Using a 25-pound mainspring may give you the best shot at swapping out the system without changing anything else, and I think that would be the way I'd go. It would also have less effect on the trigger pull.

The swap in my (hopefully) soon to arrive GI Mil-Spec will be a lot less
"iffy" since it's mainly a matter using standard springs and watching for signs of slide/magazine timing problems.

Luck!

Tuner

[Brian D.]

Thanks Mr Tuner, that's sort of what I was thinking. The ILS giz-whiz doesn't bother me any, especially given the fact that it CANNOT be activated whenever the hammer is cocked. So, if you're keeping the piece ready to go, it'll go. The gun ejects/extracts and such pretty well as is. "If it ain't hittin' sour notes don't Tune it" I always say...:D

[1911Tuner]

Brian said:

"If it ain't hittin' sour notes don't Tune it" I always say.

Yessir...About 2 dozen of my pistols...mostly GI's, a couple of ORM 91-A1s
two LW Commanders and...so it seems...a Norinco that have needed
ZERO tunin', tweakin,' fluffin' or buffin'. Well...okay. One of the
91-A1 Colts did need an extractor tweak after about 5 years...but that's it! I swear!:p

Vrooooom!

Tunerfish