15# ISMI mainsprings.......Anyone tried?

[ipscjoe]

Anyone tried a 15# ISMI mainspring in their 1911 yet?..........Had friend try one and would get ocasional light strikes with a standard length firing pin...........Was thinking of try this spring with an extra long firing pin.......

Joe

[HSMITH]

It should light primers OK if the rest of the system is ready for a spring that light, will need a VERY light hammer and long firing pin to run it.

Also be aware that the mainspring has a very pronounced affect on slide speed.

I have tried 15's, and lots of others. I run 17# springs, feel and speeds are what I like, and plenty of oomph to light rifle primers.

[BSeevers]

Dont like them. Got some to sell cheap.

[XRe]

I run 17# springs, feel and speeds are what I like, and plenty of oomph to light rifle primers.

+1. You should be able to get a very light trigger job w/ a 17# main spring, and to my feel, you pick up a lot of hammer speed with those 2#.... I don't know how much lock time actually affects anything, but with a 15# spring in my gun, it feels like it takes all day for the hammer to fall...

[Kingman]

with a 15# a dlask hammer and all Ti parts internally I would get light strikes on winchester small rifle primers. With federals it went bang.

[steel1212]

I've got a 15# in my SS 9mm that has seen TONS of ammo through it. It goes bang every, me kocking on my wooden desk, but its more of a trial that a like. I much perfer the 17# spring to the 15 and I use a 19 in a new gun for reliablity until it breaks in a touch.

[buddy_fuentes]

My steel gun has the 15# mainspring from ISMI and I use Winchester primers with no problems. The trigger parts are are stock. Press trigger and hear a boom every time.

Buddy

[03k64]

Also be aware that the mainspring has a very pronounced affect on slide speed.

Can someone explain this to me? I tried a 17# in my 1911 today and noticed the slide was a lot slower than usual. I thought it was the cold temps affecting my grease.

[HSMITH]

The recoil spring is at full extension when the gun fires and doesn't have much pressure holding the slide in battery. The mainspring however requires a LOT more tension to compress when the hammer is down.

Rack your slide a couple times with the hammer cocked, then drop the hammer and rack the slide. Feel the difference?

Light mainsprings don't provide as much resistance in the first part of slide travel that heavier springs do so the slide goes faster, less energy was used compressing a lighter mainspring and that energy remains with the slide.

[03k64]

Thanks for the explaination. I guess it was the cold and the grease slowing down the slide since my lighter mainspring should have sped up the slide.