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polymer mainspring housing for Mil-Spec Springfield

Discussion in '1911 Forums' started by seamaster, Feb 6, 2010.

  1. seamaster


    Feb 19, 2003
    I'm new to 1911's and could use your advice. I have a new stainless Springfield Mil-Spec 1911 and I would like to change to a flat mainspring housing and if I can reduce a little weight using a polymer part I'd like that.

    I found two polymer options at Midwayusa and that's a Colt made part and a Kimber. Has anyone used either of these?

    In the listing photos the Kimber shows a mainspring cap pin and the colt shows an empy hole...does the kimber come with that part?

    Also, the colt has vertical grooves and the kimber is checkered, should this be a consideration?

    Any advice you can give me is appreciated.

    Last edited: Feb 6, 2010
  2. You're the first person That I've seen WANT to put a polymer M.S. housing in his gun.
    The weight of the steel housing is not enough to matter and the durability of the steel is worth the added ounce of weight.
    I would magine that someone on this forum would have the polymer part that they took out of their gun after getting the steel part and would gladly send it to you.
    As far as the internal parts coming with the new one, not sure about that but it is very easy to take it apart and use the original parts.
    The lines or checkering are your choice to make. If the front strap is checkered or has lines I would try to match the rear also. If not then it doesn't matter.
    The weight savings is next to nothing. I would go with stainless over the polymer.

  3. myanof


    Dec 2, 2005
    Dallas, Texas
    I just installed a VZ Aluminum MSH on my Defender that I bought at Brownells. It is light and works great. The 20LPI was a bit aggressive, but after a little smoothing with a file it feels good.

  4. Brucev


    Jul 19, 2009
    Welcome to the big wonderful world of 1911's. The SA Mil. Spec. 1911 is a great pistol... stainless steel only makes it better. I hope you will be as satisfied with your new SA Mi. Spec. as I have been with mine.

    The steel main spring housing is not that heavy... but if you want to lighten up the pistol, going polymer with the mainspring housing will cut about an ounce or two off the total weight.

    Regarding grooves or checkering, I've used both types. I much prefer the checkered mainspring housing as it helps keep the gun in place. My Mil. Spec. came with an arched grooved mainspring housing. As soon as I can work things out, I fully intent to install a simple flat checkered parkerized mainspring housing. Sincerely. Brucev.
  5. seamaster


    Feb 19, 2003
    I read that the polymer part reduces weight by 1.5 ounces. That's worthwhile for me to look into. I like the looks of the fully checkered so I'll probably to that route.

    I know I want a longer trigger and if I'm opening it up to change the mainspring housing should I swap the trigger at the same time?