As Issued 1944 IBM M1 Carbine

[Newscotlander]

After close examination of some of the photos, the possibility exists that the rear sight was originally on a late Winchester carbine. Does anyone (except BQ) know why? A hint. It's been discussed in the Carbine Club Newsletters within the last 10 years.

[deldriver]

After close examination of some of the photos, the possibility exists that the rear sight was originally on a late Winchester carbine. Does anyone (except BQ) know why? A hint. It's been discussed in the Carbine Club Newsletters within the last 10 years.

This won't be the answer you're looking for, but from my own experience and what I've seen on other adjustable sighted Winchester carbines, they tended to stake the right side of the dovetail and not so much the left; not saying it never happened, but it's a definite pattern I've seen. Inland for instance tended to stake the front and back of the right side and once over on the left side (front I think). Again, I've seen some staking that didn't follow any of the patterns I just mentioned that was probably factory original. The only other thing without looking at my CCNL's (at work now) would be the shape of the punch used. Anyway, I hope you find your answer...sounds like an interesting bit of trivia there.

[Newscotlander]

On factory installed adjustable rear sights, the location of the staking is directly related to where the notches are in the base of the sight. Some early milled adjustable rear sights had the notches on the rear of the base, left and right sides. Later milled adjustable rear sights and all stamped adjustable rear sights had the notches on the right side, front and back. I'm sure this change was made to facilitate installation. The early milled sights would of had the sight ramp moved to one side to stake and then moved to the other side to get the other staking. Later sights would of only needed the sight ramp be moved to the left side to allow for staking. Below is an example of a early milled rear sight and a later one.

[DaveHH]

Only notches are on the left side.

[Newscotlander]

Only notches are on the left side.

I think you mean right side. Or let's say starboard. That's what I see.

[deldriver]

Only notches are on the left side.
https://www.milsurps.com/images/impo...0d28c7_z-1.jpg

All three of my late Winchester carbines with original adjustable sights are staked only on the right or starboard side. That was the point I was trying to make say versus Inland who sometimes did it differently from what I've seen on my own Inland carbines with original adjustable rear sights.

[Newscotlander]

Original Inland carbines will have the rear sights staked in a way that would conform to the notches on the rear sight. So, they could be staked on the right side, front and back or at the rear, right and left, as in the photo I posted above. The staking should conform to the notches on the rear sight. Now, I have seen rebuilt/refurbished carbines that were staked in other locations, but this was probably because it was the only way to get the rear sight tight. Below are two examples of milled adjustable rear sights with the earlier rear, right and left notches showing the staking on original Inland carbines.

NOTE: The staking has nothing to do with why I think the stamped adjustable rear sight on the OP's IBM is from a Winchester carbine.

[DaveHH]

Sorry Chris,
I probably had too many glasses of Port before posting.

[Newscotlander]

Been there.

[wtmr]

lol too many times