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M1 Carbine loose rear sight…update: success!

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November 06, 2021, 06:45 PM
m1009
M1 Carbine loose rear sight…update: success!
Asking the brain trust here for advice. Just picked up a gorgeous IBM M1 carbine, circa 1943-44. Didn’t notice at the time, but rear sight was pretty loose. Figured, oh, just restake it. Removed the sight, and somebody had boogered up staking it previously, to the point where they staked it two times in the front and in the back, to the extent it actually punched a bit thru the receiver dovetail. Don’t want to ruin the receiver dovetail any more than it is, what are my options for tightening it up?
Thanks in advance.


Updated: Did the can shim, nice and tight now. Also realized the rear sight IS a type 2, not a 3 as I initially thought. My excuse is I didn’t have it in front of me, and memory fades fast theses days Big Grin
Tried it it out and it stayed put. Thanks for everybody’s help, and M1Garandy, appreciate your offer, nice of you, but we are good.

This message has been edited. Last edited by: m1009,
November 06, 2021, 06:58 PM
M1Garandy
Which style rear sight?
November 06, 2021, 07:18 PM
m1009
Adjustable sight, with knurled knob. Believe a type 3.
November 06, 2021, 07:39 PM
357fuzz
Just spitballing here. A brass shim?
November 06, 2021, 07:42 PM
cas
Loctite, even expoy. Assuming you're not planning on storming Normandy beach with it. Wink


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November 06, 2021, 07:44 PM
M1Garandy
The TIII (stamped) rear sight is kind of flimsy compared to the TII (milled) rear sight in my opinion.

The first thing I would do is confirm where in the dovetail that the rear sight needs to be at when centered to shoot to POA for windage. Some have to be drifted pretty far left to zero in my experience.

From there, you can try and salvage your existing sight by restaking if it won't jazz things up worse and you are married to that rear sight and never want to remove it again.

You might also try a beer can shim under the sight before installation to try and tighten up a poor fitting sight.

Another option is to degrease the dovetail and the rear sight and Loctite it in place.

Yet another option is to replace with a TII rear sight and use any of the above to retain it.

The dovetail is tapered, and you should only drive out in one direction. Careful with and around peened spots, there are Carbines out there with chunks of dovetail broken off.

Another option that I would not do to a GI sight, would be to get a Kensight repro TII rear sight ($37 at Midway right now) and drill and tap the base for a setscrew or two to lock it into the dovetail. No staking required, you can fit as needed and if you Loctite the setscrews, they might hold pretty well.

I might have an extra GI rear sight if you decide you need one.
November 06, 2021, 08:00 PM
m1009
Thanks, all.
M1Garandy, the shim sounds like a good plan. I think we will try the can shim tomorrow, and see how it goes. Like I said, really don’t want to try staking it again, as I didn’t like the looks of the last couple attempts somebody made and I don’t want to make it worse by another staking attempt. Might have to go the loctite route if shim doesn’t hold.
Thanks for the info on the Kensight, not sure if we will go that route yet, but good to know if we need one down the road.
Will let you know how it works tomorrow. Keeping fingers crossed!
Appreciate all the info!
November 07, 2021, 12:35 AM
Shackelford
Brass shim is what I did. Picked up a roll of thin brass sheet. Cut a couple pieces to fit the size of the dovetail and put it under the sight. Restaked, and at this point probably have a thousand rounds through the gun. Simple fix.
November 07, 2021, 07:24 AM
m1009
Thanks, Shackelford. Hadn’t thought of brass, but then we don’t have any around and would have to go get some.
Will check it out today, and post results after. Appreciate all the info, and help.
It’s a nice IBM, no pitting, and original IBM barrel, too.
November 07, 2021, 11:22 AM
PGT
I had an Inland with a rear sight that would just fall out. Staking it wasn't enough...like a lot of moved metal underneath to fill the gap by raising the bottom of the sight itself. I fixed by using the field expedient recommended repair of of brass sheet cut as a shim. Hasn't moved since.
November 07, 2021, 11:41 AM
MikeinNC
You can cut a 223 case with a hacksaw and snips and make shims out of that…I’m sure you have an empty case layin about somewhere



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November 07, 2021, 03:49 PM
m1009
Updated, also in original post.
The can shim worked perfectly. Rear sight is nice and tight, no movement. Test fired and still rock solid. So thank you to everybody who replied, it was very helpful! Big Grin