Dedicated M1911 Receiver for .22 cal. Conversion

I will either build or have built a M1911 receiver that I will use only for a .22 cal. conversion.  If anyone here has done this, and it is pretty common, have you done anything differently, other than trigger weight, than you would have done for a .45?

Mainspring - have you used a standard weight (17# I think) mainspring or did you go lighter so the slide has an easier time of recocking the hammer?

Mainspring housing - flat or arched and for what reason(s)

Any other thoughts or ideas?  My conversion unit is one from Advantage Arms.

Thanks.

Hi James,

You are taking on a fun project!
I did a build and tried about everything....so I have some experience with what doesn't work.
Most people say that a 23# mainspring is "standard" for a 1911.
17# is too light.  I found that the Wolff 18# is as light as you can go to avoid hits.  I am using 19# ISMI mainsprings in all of my 1911s.  Yes, I like the lighter mainsprings so the slide can move easier.

For CCI SV you will need a 7# or 8# recoil spring.  I like to order them from Marvel because they paint the end of the recoil spring so you know which spring is in the conversion.  They even sell a handy variety pack.

I also use an Advantage Arms.

arched or flat Mainspring housing? it doesn't matter. Most shooters don't have a big enough hand to use an arched mainspring, but it's all a matter of preference.  You could have a whole thread full of a contentious debate on that topic.

Even though I have this lower, I don't use it.  I just switch back and forth from my primary .45.  It helps me learn the trigger better.

Ditto on the 18# or 19# mainspring.  You can also leave the ejector off of the frame if it is dedicated to the conversion unit since it serves no function.

One other thing.  We usually stay away from stainless on bullseye guns because of the tendency to gall when closely fit.  On a dedicated lower feel free to go stainless.  The slide runs freely with no close fit so there is no galling to worry about.

Dr. Don,

DO NOT leave off the frame mounted ejector from the dedicated frame.  It acts as a gas deflector if you have a blown or perforated .22 LR.

Don Nygord was emphatic about this when he built my Nygord-Kart 5" on a Colt pre-Series
70 lower end.

Jerry Lehrer

Good point Jerry.  I'll have to put one on mine.