Optimizing 1911 for Marvel .22lr

[Titurel]

I have a Springfield WWll style 1911A1 (made in Brazil) that has become a dedicated host to a Marvel Unit 2 .22lr conversion. It is one of my favorite pistols to shoot and has been a great project for me to learn about 1911's. So far I have changed the main and sear springs and installed a flat housing and some wood grips. The trigger still needs work.

Are there any modifications to the gun that would improve it's reliability with the Marvel conversion? It runs fairly well with certain ammo but I cannot use anything match grade and overall things could be better. I realize that many of the variables are within the Marvel unit itself (such as the recoil spring), but I thought it might be advantageous to alter some things on the host gun.

Note that this pistol will never again be used to fire .45acp Therefore I am not concerned about compromising it's functionality as a "real" 1911 if I can gain some more reliability with the Marvel. One possibility would be to go with a very light mainspring, thereby reducing the resistance to the slide moving rearwards. This assumes (perhaps incorrectly) that .22lr needs less hammer impact for ignition than .45acp

Anyway, I would appreciate any suggestions or thoughts about this. Thanks!

http://i48.tinypic.com/x0z43k.jpg

[Quack]

what "match" ammo are you using?
the ammo for the Marvel Unit 2 needs to be high velocity ammo.
My Wilson/Marvel Unit 2 will eat any high velocity ammo including Remington Golden Bullet, but i haven't tried my Wolf Match ammo, since i know that it doesn't run with standard velocity ammo.

you could try a few different things, such as a lighter mainspring and recoil spring.
since this will be a dedicated .22LR, get a few springs, and start clipping coils to find what works. you could also look for lighter (titanium) parts such as MS cap, hammer strut and a lighter hammer as well.

[Titurel]

Thanks for the reply. I went ahead and ordered a few things from Midway to tinker with: some light weight springs, titanium strut and a new hammer. The face of the current hammer looks very chewed up, so that may be a source of unnecessary resistance to the slide cycling. I Also got some Kimber .22lr magazines from them (which supposedly function well in the Marvel). My original Marvel magazines (which appear to be Metalform Colt Ace magazines) are looking pretty beat up and may also have been causing some of my problems.

I realize that the Marvel specifies HV ammo for the Unit 2. Mine also does pretty well with Golden Bullets. Still, overall reliability could be better and it would be nice to use ammo that fulfills the accuracy potential of the gun.

[Quack]

The kimber mags work well with the marvel kit.

[Jim Watson]

This assumes (perhaps incorrectly) that .22lr needs less hammer impact for ignition than .45acp

Rimfires take a harder blow to fire than centerfires. You might be able to reduce the mainspring a little but not as far as you could for a centerfire which will do just fine with a 19 lb mainspring or even a 17 instead of the GI 23.