1911 Mainspring Swapping


December 3, 2006, 01:35 AM
Need a last minute review of procedures I am planning for tomorrow...

I have read the Springfield manual on ILS M.S. removal and done web searches and forum reviews...(which led me here). Also waiting on the Ed Brown DVD and Jerry K? 1911 gunshop manual to arrive soon.

1. Kimber 5" (no night sights) just had a SA M.S./magwell custom installed and have traded a Sig for a Springfield Loaded 5" which I test fired and am planning on carrying on duty. The Springfield has Novak nightsights hence my project. Planning on swapping the SA mainspring/magwell from the Kimber to the Sprgfld and the ILS to the Kimber (temporary)

Just to be sure... I need to have hammer forward on lower receiver and grip safeties held with rubber band. Brass punch the pin from frame to remove mainsprings. Swap and check for proper fit. Assure of "sear"? spring into mainspring "hole" and reseat frame pins.

2. Kimber has full length guide rod - Springfield has Ed Brown "short" rod. Which do you prefer? and swapping should be no problem keeping rods/springs/plugs together...correct???

3. When i replace the ILS M.S. i will need to get the replacement M.S. housing and new "guts" since i read the ILS plug/spring set is of differing lengths... correct???

Thanks for any and all assistance in this project. I do look forward to making great use of this site!


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December 4, 2006, 06:26 AM
1. Yes, but its so much easier to do it than to explain it. I use a dowel to push the MSH retaining pins out, they come out pretty easily. You dont even *need* to remove the slide to do it. Rubber banding the grip safety makes reassembly much easier though.

2. I prefer traditional plug/rod. It has more options for press checking/racking the slide and is lighter.

3. Yes, you'll need new guts too. As a matter of fact I have a MSH assembly for sale in the buy/sell/trade accessories section right now if you're interested.

December 4, 2006, 07:57 AM
I bought a Springfield G.I. and replaced the ILS with the following...

Ed Brown blued flat mainspring housing (Brownell's #087-816-120)
Wilson Combat mainspring cap (Brownell's #965-011-161)
Wilson Combat mainspring cap pin (Brownell's #965-011-165)
Wilson Combat mainspring pin retainer (Brownell's #965-011-163)
Colt mainspring housing pin (Brownell's #160-116-133)

ETA: eliminate confusion on what is needed...

This should be everything you need.

Hope this helps you...:)

December 4, 2006, 06:52 PM
I was not aware of the hammer spring and sear mandatory replacement if removing the ILS mainspring. This adds new problems....

Thanks to those who replied - learned much

December 4, 2006, 07:13 PM
I don't think you need a new sear spring. The ILS is contained completely in the mainspring housing. Replace the mainspring housing and mainspring and you are good to go.

December 4, 2006, 09:36 PM
Sorry... should have worded it differently. If you are paying for the compenents in the C and S trigger pull set you might as well use them, otherwise you don't have to.

December 4, 2006, 10:31 PM
ok sounds good - thanks for all the assistance to all.

December 5, 2006, 09:23 AM
You don't need to replace the hammer and sear etc do you? I thought the ILS just locks the mainspring so it can't exert force on the hammer? I don't think you need to spend a whole mess of cash for a new ignition set.

December 5, 2006, 04:11 PM
No, you don't need to replace the hammer and sear. I confused everyone by including the c and s trigger pull set. You don't have to replace the hammer and sear, just use the stock parts...

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