1911s dropping mainspring housing pins


July 31, 2006, 05:57 PM
Two of my Colt Combat Commanders are losing their mainspring housing pins during shooting. Both came with arched housings, but I do better with flat ones, so over time I've ordered flats made by Masen and Brown. Both were stiff going in so I did a little filing to fit them. Maybe I'm missing the deal here, and I don't see this topic in Kuhnhausen's book.
Where should the material removal be on MSHs?

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Ron James
July 31, 2006, 06:08 PM
Im afraid to ask , where did you do the filing? If on the pin, replace the pins. If on the frame then you steped in doo - doo. You could try and stake the pins, should work. I don't know if you ruined the frames or not, you may have to have the holes redrilled and use a lager pin. In all my years of shooting the 45 I have never had to file the pins or frames. I have smooth the pins a little but never filed. I like the arched housing and I also like to tinker with my 45s so yes I've removed and replace a lot of main spring housings

July 31, 2006, 07:16 PM
The pin that holds the spring assembly [cap, spring and plug] in place in the housing?? Or the pin that holds the housing in place in the gun??

July 31, 2006, 08:00 PM
I filed the upper ends of the housings themselves, which seemed to be where the tightness was, based on inking the housings, installing them, and taking them back out to see where the friction came from.
The mainsprings aren't pushing the housing down hard enough to keep the pins in place.
File pins? That sounds hard!

July 31, 2006, 08:16 PM
Is the pin retainer (part #62 on this schematic) that fits on the bottom of the mainspring (hammer spring) still in place on the bottom of the mainspring?


This part is necessary to hold the MSH pin in. In addition, the MSH pin should have a groove in it's center that this retainer presses against. A mainspring (hammer spring) that is not long enough may not exert enough pressure to keep the pin in. If you are missing part #27, the upper MSH pin, that holds all the mainspring assembly in the housing, There may not be enough pressure exerted by the mainspring with the hammer released to retain the lower pin. Pin #27 helps keep the mainspring under compression as well as containing everything for MSH assembly removal.

Some of the less expensive mainspring housings such as the Massen just aren't drilled enough to allow proper seating of the retainer, or they may have a burr inside preventing it's seating. You should be able to see a bit of the retainer looking through the pin hole. Take a .22 caliber bore brush on a Dremel and polish up the inside of the MSH and then wash it out well. This will at least polish the channel the parts slide in.

When I fit a MSH, I usually use a Brown or S&A unit. Almost always, if it needs to be fitted, all that is necessary is a bit of filing on the forward face that fits right below the sear spring against the frame. You will note on a MSH this area is raised just a tad to make contact with the frame while allowing a small space for the sear spring above it. If you were using a marker to help you fit the MSH, then you no doubt did fine.

July 31, 2006, 08:35 PM
If the guns have been detail stripped, it's possible that the mainspring housing pins got switched with the hammer pins. They're the same size, but they're not the same. The housing pin has a groove in the center and a dimple on one end. If there's no groove, the retainer won't help.

Ron James
August 1, 2006, 09:21 PM
Cherryriver, sometimes I get tunnel vision, I could only picture someone with a swiss file enlarging the frame hole. Sorry about that. I think 1911Tuner is right on the money.

August 1, 2006, 10:05 PM
Almost forgot...Even if the pins haven't been switched, if the plunger/retainer isn't pointy, it won't get a bite in the groove, and the pin can walk out...but it has to be pretty badly rounded off.

Jim K
August 1, 2006, 11:10 PM
I hate to mention this, but some of the after market MSH's don't have the spring hole drilled through, so the mainspring housing pin retainer doesn't contact the mainspring housing pin at all. That is the first thing I would check. I once called a manufacturer on that and the reply was, "Huh?"


August 2, 2006, 07:51 AM
Jim brought up a good point. I've run into that once. The hole was drilled, but not quite far enough to let the pointy end engage the groove in the pin.
With the housing assembled, hold it up to a light and look through the hole to see if you can see the end of the plunger in the hole.

August 4, 2006, 05:10 PM
I think my feelings may be a bit wounded to imagine my Internet correspondents suggesting that I, a lifetime 1911 owner, a fellow who has had his ancient Combat Commander under the figurative pillow every night for three and a half decades, could possibly have neglected to emplace the lower mainspring retaining pin while installing aftermarket mainspring housings. How could they think such a thing?
I suppose I'd carry on a bit on that line had I not just located two orphan retaining pins in a Les Baer baggy in the parts bin.
A marvelous thing, this Internet. One can be embarrassed in front of multitudes so efficiently and with so little effort!
Thanks for the help.

August 4, 2006, 07:02 PM
Well cherry...

Ya didn't SAY that you were familiar with 1911s...and from what I've seen here, nobody meant to do anything except offer some help.

You're welcome...

August 4, 2006, 08:45 PM
Cherry...1911Tuner and the rest mean no offense, they're here to help. SInce they cannot physically see what you've got, all they can do is stab in the dark based on their experience and knowlege, leaving no stone unturned looking for possibilities (even the most simple (stupid things if you will) of conditions you might encounter) . It's up to you to sort all the information and come to the proper conclusion.:)

August 4, 2006, 09:21 PM
Gentlemen! I was being facetious! Actually, I hardly know any other way to be.
Something stupid was what I did, leaving out these parts. For a guy who spends his days taking houses apart and putting them back together, leaving out parts is a really, really Bad Thing.

Jim K
August 4, 2006, 09:25 PM
Well, if I had a dollar for every time I have made an error or been embarassed by something I posted on the Intenet, I could be buying out Bill Gates right now.


August 4, 2006, 09:33 PM
Ah! Good show then!:cool:

Jim K
August 4, 2006, 09:49 PM
Off topic, but here is a story a builder might appreciate.

I once saw a cartoon depicting a building site. The building was huge, so tall that the top was surrounded by clouds. It was ribbon cutting time, the speakers' platform was draped with bunting, and the VIPs were arriving.

In the foreground, were the architect with his blueprints, the money man with his briefcase and homburg hat, and the construction engineer with his bulging muscles. They are all looking up at the huge building and one says, "Oh, my God, we forgot the rest rooms."

Now THAT is a goof!


August 4, 2006, 10:17 PM
Now I'll tell one...on me!:rolleyes:

Now most here know that I've been wrenchin' on 1911s on and off for the last four decades and change. Okay...

Had a little quickie tweak job about three years ago. Install an oversized firing pin stop and a new extractor. I did the stop, then turned to the extractor. Did the usual stuff, and things didn't feel just right...so I removed it and checked the feeding without it to see what page I was on. In/out 3 or 4 times. Got it worked out...removed it again to check the feeding without it. Good to go. Slapped'er together and stepped outside to test-fire it...and promptly had a failure to extract.


Cleared the jam and tried again. Same thing. :cuss:

Went back inside to re-tweak the extractor...and there it was, layin' on the bench. Almost seemed like it was askin: Are you THAT stupid??:rolleyes:

One of these days, I swear...I'm gonna hunt Murphy down and shoot him like the mangy cur that he is...

August 4, 2006, 10:21 PM
You did install the firing pin!:neener:

kart racer
August 4, 2006, 11:31 PM
Tuner did have this one time with a springer mil spec trigger and grip safety problem...uh what was it...the lock system:D Please don't ban me,we got to go shoot the rifles.
Oh, I sent my upper away to stag ar15 for the front sight being canted-they seem about as good as springfield on warranty stuff.
ps see my sig,I just couldn't stay silent..

August 4, 2006, 11:57 PM
Want to know how I went straight to that possibility? I've done the same thing. :o
Glad it's ironed out!

August 5, 2006, 10:16 AM
heh heh...Joe, that thing had me scratchin' my head for a minute. Still can't figger out how it happened...and can't even remember exactly why it did that.:rolleyes:

Murphy...I'm gonna find him one day, and it'll be payback time!:fire:

August 5, 2006, 10:45 AM
Ya'lls stories are from the mouths of rank amateurs.... take it from a perfesshnul screw-up.

Y'ever rebuild a carbuerator and end up with an extra screw and two extra nuts and all seems to be re-assembled??:uhoh: :scrutiny: :cuss: :rolleyes: :eek: :what: :p

August 5, 2006, 12:41 PM
Knowledge paid for the hard way is the very best and most useful kind.
Thanks for pointing out the un-obvious obvious.

August 6, 2006, 10:58 AM
Y'ever rebuild a carbuerator and end up with an extra screw and two extra nuts and all seems to be re-assembled??

Or RnR an engine or tranny and have a handfull of case hardened bolts about 4" long left over?:eek:

August 6, 2006, 07:15 PM
Y'ever rebuild a carbuerator and end up with an extra screw and two extra nuts and all seems to be re-assembled??

Or RnR an engine or tranny and have a handfull of case hardened bolts about 4" long left over?
Yesterday 04:41 PM

Man, thats one of the funniest/cruelest things to do to a wrench. Throw a couple of long bolts that you have laying around the shop into the other guys parts pile. Then stand back and watch the fun.

August 6, 2006, 08:16 PM
Man...you are just MEAN!:evil:

August 8, 2006, 06:55 AM
And the cruelest thing about it is? drum roll..... Pull out a bolt and replace it with a look alike with a different thread pitch. Then watch the fun begin. :D

August 8, 2006, 08:50 AM
My job includes issuing out hardware to maintenance. When they ask for 30 or more (standard) bolts/flats/locks/ and nuts, YOU KNOW...I've GOT to throw a few fine thread nuts in the pile. If I'm really feeling evil, METRIC nuts. Some things just make life worth living...like the confusion and irritation I hit these guys with. On the same note, they walk in and say "I need a bolt". We carry from 1/4" x 3/8 to 1-1/2" x 14" bolts (all sizes in between plus assorted metric), and they need a bolt!!! My response is..."did you have a size in mind or is it my choice?". Some people in MAINTENANCE actually will ask for a bolt by the size wrench that fits the head (eg. 1/2" takes a 3/4" wrench). Keep in mind, these guys are college educated journeyman and apprentices in the maintenance and die repair fields.:what:

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