M1 carbine rear sight fell off

[Henry Bowman]

The other night (while cleaning my guns and watching the Reagan funeral), the rear sight fell off of my M1 carbine. It had not appeared loose before, and now it will slide from side to side all the way through the dovetail with only a minor "catch" or friction. There is no set screw or anything. What is supposed to hold this in place?

Any suggestions?

 

[Ed]

It is an adjustable sight right? It is staked in right in front of the sight on the reciever. If you look close you will see the marks. If it is a USGI Reciever. If there are no marks then you are lucky and could restore it to origional OLD M1 carbine flip sight style. When they replaced the flips with the adjustable they staked them, so people who want it to be as close to As issued and need to put a flip back on still have the tell tale stake marks. I say all that because I assume that it had the adjustable, Later carbines were made that way and the others were mostly converted. Sorry I rambled so much.

 

[Cortland]

I recently received a BP pistol with a front sight that was loose in its dovetail.

You can tighten up a dovetail by peening it in with a wide punch and a heavy hammer. Align the punch along the extending edge of the dovetail and give it a gentle whack with the hammer. Continue down the dovetail, then move to the other side. Go slowly and start lightly. As you do this, try the sight back in the dovetail. It should be tighter. Continue peening until the sight fits tightly (i.e., you have to drift it back into place).

 

[Henry Bowman]

Thank you both.

Ed - Yes, it is an adjustable, not a flip. I cannot see any marks. Perhaps I'll look for a flip sight to replace it with before I do anything to it.

 

[Cortland]

Here are pictures of the different sights.

 

[Henry Bowman]

Mine has (had) the one in the middle.

 

[Ed]

The flips are cool, But I guess I should tell you before you spend money on it that if you put in a flip, you will probably have to replace the front sight too. There were different height sights for the different rears.

 

[Henry Bowman]

Thanks for the tip. Mine is not particularly collectable -- just fun to shoot -- and I don't want to replace the front sight.

 

[M2 Carbine]

Henry,
One of the easiest ways I've used to lock in the rear Carbine sight is with JB Weld.
I've tried peening and sometimes the sight will stay in place but sometimes not and it never looks good.

JB Weld is some tough stuff so you have to figure the sight is there to stay.

Clean and degrease the sight bottom and receiver dovetail good.
As a side note, anything I don't want the JBW to stick to I spray with WD40.

Use as little JB Weld as possible and clean off any that gets on the sight and receiver before it sets up. It takes hours to set up and will run like soft mud until it sets up.

You might even try "welding" a couple small scrap pieces of metal together before you try the Carbine sight to see if you want to go that route.

 

[Cortland]

I'm not sure about the properties of JB Weld, but most conventional epoxies will break down around 400 degrees; so removal should be possible with the aid of a propane torch.

 

[444]

Could someone please explain to me about the front sights (sorry, not trying to Hijack) ?
My carbine shot about a foot high at 100 yards. I showed it to a local guy who said it looked like the front sight had been filed down. He said he had one, follow him home and he would fix it. Sure enough, the sight he had was significantly taller than mine. He changed them out. I took it out again the other day and it still shoots way high. Probably 8" high at 100 yards. So, now I wonder if my sight was filed down and his was the old one from before they got the windage adjustable rear sight ?
Is there any way to tell what you have ? Or how to order a new one that is taller yet ?

 

[M2 Carbine]

Cortland,
I don't know what temp JB Weld will take but I used a bead of the stuff to hold a 1.5 inch long aluminum pipe to a round aluminum muffler on a radio controlled helicopter.
I was surprised it held at all but it lasted a long time.
That made me a believer in the stuff.


444,
I just check 4 Carbines that I have handy.
3 have filed down sights.
The 4th doesn't look filed down.

I'm not sure if this is a positive way to tell if your sight has not been lowered but the flat on the very top of the sight blade should be almost square.

As the sight is filed down, of course the top becomes longer.

And this sight blade is exactly 5/16 inch high.

If you can find a carbine parts seller at a gun show you can compare the sights he has on hand.
In the past the ones I've seen have all mostly been filed down.

 

[444]

Ok, mine is the same: .318" which held up to a ruler appears to be about 5/16"
Why would anyone file down the front sight ? Why wouldn't you want the rifle to shoot where the graduations on the rear sight say it will shoot ? I would be willing to bet that my carbine would hit dead on at around 350 yards with the rear sight set at 100 yards. No matter the distance, whatever it is it is far beyond the effective range of the carbine. And the sight that came with the carbine was worse. It shot over a foot high at 100 yards with the sight set on 100 yards.
Do you think the 5/16" sight is the "new" or the "old" height ?

 

[M2 Carbine]

I'll check my other Carbines tomorrow but I bet 5/16 is the unaltered height.
I haven't had any of the old sights so I don't know what the front sight requirement would be.

It's been years ago but I think I filled down one or two sights myself because the rifles were shooting too low with the rear sight all the way down.

 

[Ed]

I had one that had the old front sight, but the rear had been changed to the adjustable. Well, the carbine shot about a foot high at 100 yards. What I did was go to Wal-Mart and get some of the metal putty stuff, its used to fix radiators and stuff, like clay but it hardens to like metal. Anyways, I put it on the front sight and let it harden, then used an exacto knife and file to shape it. Then you have a higher front sight without changing anything and with a perminant marker, you really cant tell that you did anything. Remember, lots of the carbines were used by officers, or folks in support positions. When the sights were changed out, these people probably shot it once or twice to qualify, if that. And in a battle, if it was fired it wasn't at a target.

 

[Henry Bowman]

Again, thanks for the tips. I've worked with JB Weld and given that the sight didn't appear loose until it fell off, that may be the better way to go. My only concern is trying to center it so that I don't have to use the windage adjustment to center it. Peening and drifting would be better in that regard.

Regarding the front sight, the elevation on mine seems OK at 100 yds, though I haven't yet precisely sighted it in.