How to swap out the Mainspring Housing on a 1911

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Push the MSH retaining pin out, pushing from the "dished" side of the pin. Pull the old MSH out. Push the new MSH in. Reinsert MSH retaining pin. Takes less time to do than it does to type out these directions.
 
Unless your tolerances are so tight you have to file off the top of the MSH to get the grip safety to move.
 
The new MSH likely won't come with the mainspring or cap so you'll need to remove the pin that retains those (keeping the thing pointed in a safe direction, preferably one that will catch the pieces when they come flying out). Put the pieces in the new MSH, insert the pin, place new MSH into 1911 and reinsert the retaining pin.
 
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Make sure you use a heavy rubber band to hold down the grip safety. This should prevent the sear spring from popping loose. Also remember to have the hammer strut end go into the mainspring cap.

2 minute swap.
 
I'm about ready to step out to friday Happy hour but will tell you how
I changed my arched stocker to a flat.

* go to brownell's they carry 10 or more different make and type of
Main SPring Housing optionss Consider what you want.

I'll be back in a couple of hours

Randall
 
I actually just did this tonight using directions from wamphyri13 as he answered my question in the 1911 forums:

01)Make sure pistol is unloaded.
02)Wrap a rubber band around the grip safety.
03)With a small punch, drift out the mainspring pin
04)Remove mainspring housing
05)Press down slightly on the mainspring cap in the housing and push out the little retainer pin.
06)Remove guts and place in new MSH.
07)Press down slightly on the mainspring cap in the housing and push in the little retainer pin.
08)Install MSH in the gun. Be sure hammer strut rests in the mainspring cap.
09*)Press the MSH firmly upward to align holes and tap in mainspring pin the same direction it came out.
10)Remove rubber bands and test function.

It was pretty simple - the only problem I had was in step #5 I was trying to push the retainer pin on the mainspring out backwards. One thing that will be helpful is to have a vice or some clamps to use when tapping things out.

This was the probably the biggest 'gunsmithing' step I've done with my handguns - the 1st one was replacing the mainspring in my Sig P226. If I can do this, just about anybody can.
 
Yeah, I got a bit confused when Josh mentioned the plunger

THe Main SPring Housing (MSH) contains
<drum rol>
l the Main SPring (MS)

The MSH has a vertical hollow space where the MS resides,
at the base of the MS it has a Cup to hold the end of the MS
it is a resting place for the MS - a coil spring.

In fitting an MSH you might need to stone the sides for vertical
fit - you might need to stone the top horizontal for that portion of
the fit. The tube that contains the MS in the new MSH should be
polished - use a rod and fine grit wet seandpaper say 400 grit to make
sure thaere aren't any burrs in the tube for free travel of the MS.

Dis-assembly and Assemboly is best left to those with experience,
I had my gunsmith do this after I got the new MSH I wanted installed
from Brownell's. He didn't charge much maybe $15?

If you do it, wear safety glasses.

Randall


THe
 
A tip for reassembly...... have the hammer at rest when reinstalling the MSH. If the hammer is cocked you will be fighting the mainspring/hammer spring and at 23 lb. it can put up quite a fight.
 
The mainspring is very difficult to compress to remove or replace. I have a small nail sticking out of a stud in my garage I call my "mainspring installation tool." If you press the mainspring cap against the nail you can get a lot of leverage very easily. Then R&Ring the pin that retains the spring is very easy.

Also, if you are replacing the housing it is a good time to consider adding a mag well. Smith & Alexander makes a really nice one that comes as one piece with the arched housing. The housing is also lined in 20 LPI checkering. I put them on full-size 1911s as a matter of routine, kind of like replacing the springs with Wolff.

Lastly, wear safety glasses when dealing with the mainspring. They are under a lot of pressure.
 
Well disregard my description of the position of the Main Spring Cup,
and erhm Loop, the O.P. said he wants to go to a FLAT MSH do mag
wells have that option?

I personally don't see the need for a mag well if the mag opening has
been beveled for ease of mag entry but to each their own.

I sent the O.P. a pic of my 1911 with a Les Baer Custom
Stainless Steel Flat w/vertical serrations MSH. This Flat MSH with the vertical serrations don't sit flush with the frame, but stick out just
a bit but it is constant in length and not the shape of an arched
where the arched sticks out further from the frame as it travels toward the
base of the handle. I find it very comfortable IT's a S&W 1911 5"
Bbl. in Stainless Steel. fwiw.

Randall
 
Well disregard my description of the position of the Main Spring Cup,
and erhm Loop, the O.P. said he wants to go to a FLAT MSH do mag
wells have that option?
Click to expand...

Yes, I have one on my Springfield. They also list them in thin to match thin grips if your preference is for thin grips.
Joe
 
+1 on Loop using the small nail on the stud. I have made a fancy one that cork in my bench vice......



A scrap of 2X4 Stud with a 6 or 8 penny finishing nali driven to about 3/8" protrusion. Mines portable....I don't have to take the garage with me to change a main spring:neener::neener:
 
Um gee, HRT, I've been working on a ccw garage, but...

Oh, sorry, S&A offer flat mainspring housings with the magwell too. I was just mentioning it because it is easy to do at the same time.

Flat mainspring housings with or without mag wells are common. Send me a check for the cost of freight and I'll send you two for the price of one. After the check clears.

I only mentioned it because it is the appropriate time to make the conversion.

my bad...
 
Loop-
You'd have to have Omar the tent maker building your cover garment for a CCW garage....even if it were for a Mini cooper....:D:D
 
HRT-

I'm a big guy. I can carry a colt in my pocket. I oughta be able to fit a garage in my armpit...

LOL
 
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