Fixing Wobble of Adjustable Rear Sight in Receiver Dovetail

[Pedantic_Potato]

Happy New Year!

I've asked this question in a previous post as an addendum and not on its own. Due to that poor inquiry strategy, I wasn't successful in getting an answer, so I'll ask it again here.

The adjustable rear sight of my Inland M1 Carbine wobbles (the base of the sight moves side to side) quite a bit in the rear sight receiver dovetail whilst dry-firing.

Any recommendations on fixing the wobble other than having it staked in place by a gunsmith?

More information: I installed the adjustable rear sight using the rear sight installation tool from Matrix. The adjustable rear sight appears to be original, but I got it with the rifle when I inherited it.

Thanks in advance!

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[painter777]

I've personally seen 2 guys that beat down small pieces of Aluminum or Brass and used as a shim. Made them short enough that they didn't show from the sides.
1 fixed by placing it behind the sight... like this /
The other by putting it under the base and slightly bent over the rear of the sight base.... sorta like this /__
Both of their methods above worked and has stayed in place and not visible.

I've 'Heard' of guys peening the front and rear edges of the very bottom of the sight where it would meet the inside corners on the dovetail cut/base corners. I'll look for a illustration in the morning that shows filing of this same area if the sight is too big / tight. Understanding we're trying the opposite to peen it out / spread for a tighter fit.

I'd try Loc-Tite first with everything degreased. If it fails I'd then try the shim.
I wouldn't do any staking or peening over the Receiver Dovetails for fear of damage or adding any ugly to them.

Hang on for other opinions as I know some here have had to repair the same issue.

[GotSnlB28]

I have used Loctite 620 retaining compound to secure adjustable sights and a flip sight. 620 has a thicker consistency than threadlocker. Now 620 was intended for cylindrical objects but I have it on hand and it worked well. One shooter rifle I must have around 1.5k+ rounds and it's holding tight with no movement.

[Pedantic_Potato]

I'd try Loc-Tite first with everything degreased. If it fails I'd then try the shim.
I wouldn't do any staking or peening over the Receiver Dovetails for fear of damage or adding any ugly to them.

Agreed, I've seen rifles that would have done better had their users not poorly staked their rear sights in place. I will follow with the shim idea if the Loctite fails to do the job adequately. Any particular type of Loctite?

I have used Loctite 620 retaining compound to secure adjustable sights and a flip sight. 620 has a thicker consistency than threadlocker. Now 620 was intended for cylindrical objects but I have it on hand and it worked well. One shooter rifle I must have around 1.5k+ rounds and it's holding tight with no movement.

Nice, I will have to run down to the hardware store and pick some of that up to try out.

[floydthecat]

I never have been a fan of glue or shims on a gun. If the rear sight is not a rarity, remove it and wind the ramp to either extreme, drill a small hole thru the top of the base and thread it for a set-screw. The screw should be flush or slightly below the surface so the ramp can be ran over the top of it. Set-screws are routinely used on sight bases and I recall seeing a early experimental adjustable carbine sight that had a set screw in it’s design.

[painter777]

I talked (emailed) with one of the guys I mentioned above who used a shim for his Adj sight.
I was wrong it wasn't brass it was copper.

From our Email:

" Wasn't brass, I had to smash out a piece of copper shim for the rear sight. In a squared U shape with the uprights just tall enough to rise above the front and back grooves on the sight. Once I had it beat down thin enough I placed it over the bottom of the sight and folded the edges. Made it about 3/4 as wide as the sights base. It's still rock solid with no movement after over 2 1/2 years later being shot Damn near every week. We don't have to stand in snow drifts down here to shoot! Thanks again for the receiver, stock and the other parts"

From personal experience I've had 1 Rear Adj that had some side to side movement. Noticed when my shots were randomly walking left or right in one shooting session. After getting it back home I lined it up with the original stake marks and put a drop or two of the Blue Loc-Tite right on the punch marks (from the top). This is one of my most used shooters and has held up for probably 5 years now. When dry you can't see that I put it on. Probably worked because the wobble wasn't big and that this area doesn't get hot. If I had the better 620 or similar I would have used it, but thread lock was all that was in the tool box at the time. Have often wondered if a small dab of JB panel Weld Epoxy would work, I'd assume it would. I've seen truck cab corner replacements put on using these type of bonding agents and they are solid.

IMO, Anything is worth trying to keep from beating on the Dovetails........

[Pedantic_Potato]

drill a small hole thru the top of the base and thread it for a set-screw. The screw should be flush or slightly below the surface so the ramp can be ran over the top of it. Set-screws are routinely used on sight bases and I recall seeing a early experimental adjustable carbine sight that had a set screw in it’s design.

Interesting, that seems like a effective way to do it. Any advice on the size of the set screw or any specialized tools I may need to be in a position give that a shot? I would do this on a commercial reproduction sight since mine is original Inland from what I can tell.

From personal experience I've had 1 Rear Adj that had some side to side movement. Noticed when my shots were randomly walking left or right in one shooting session. After getting it back home I lined it up with the original stake marks and put a drop or two of the Blue Loc-Tite right on the punch marks (from the top). This is one of my most used shooters and has held up for probably 5 years now. When dry you can't see that I put it on. Probably worked because the wobble wasn't big and that this area doesn't get hot. If I had the better 620 or similar I would have used it, but thread lock was all that was in the tool box at the time. Have often wondered if a small dab of JB panel Weld Epoxy would work, I'd assume it would. I've seen truck cab corner replacements put on using these type of bonding agents and they are solid.

I inspected my carbine again today and it seems to wobble about 0.0470" from the leftmost position to the rightmost position (I centered it as stated in manuals for my Matrix tools and the 1942 Army FM). At this point, I plan on stripping my carbine, cataloging/photographing its parts and their markings, then removing/reinstall both the front and rear sights with the latter using Loctite. While I like flydthecat's set screw ideas, I don't have a spare reproduction rear sight to experiment on at the moment, but I'll snag one from Numrich when I place another order through them.

I've seen you in the Carbine Collector's Club Forum, painter777, would you recommend posting these questions there as well for additional answers?

[painter777]

Reply #3 and #5 above came from respected members from the CCCF site. I'd bank on their advice.
Gotta ask- Why remove your front sight? Having a issue with it ?

Until tomorrow,
Ch-P777

[Pedantic_Potato]

Copy that. Thank you all very much for your advice and that of others. It looks like I lucked out with knowledgeable folks.

Good question. I was a little less than smart when I installed it and the front blade is canted at least a couple degrees off center to the left... It's a repro front sight and the barrel is a gunsmith re-barrel (the bore of the original was worn out and mildly corroded) that lacked a front sight.

Let me put it this way, it's really cool that I inherited an M1 Carbine, but it's not so cool when it ping-ponged around family members before me that all had their own ideas of what the carbine *should* be and the will to make those ideas a reality (when I got it, my carbine had a cheap scope rail mounted in the rear sight receiver dovetail with a $15 red dot mounted atop it. Talk about a bore offset! Couldn't get cheek weld to save my life!).

Add to all of this a bad roll of the celestial dice regarding 1984 Korean surplus .30 Carbine from SGAmmo (about a quarter of the 1080 rounds have the green/blue corrosion on the brass cases/up the sides of the bullets themselves), and it's safe to say that I've had quite a few less than stellar experiences with my M1 Carbine. That's not to say I don't like the rifle, but I just can't seem to catch a break haha. Sorry for the ranting/rabbit trailing. Here's to hoping my streak ends!

[DaveHH]

Some Loktite info if you plan on using that fix:

When my new Tech sights kept coming loose on my 10/22, The owner told me a piece of info that I'd never heard: Loktite has a shelf life. In other words, when it is old stuff, it doesn't work. Since you only use a tiny amount of the stuff, there's probably a lot of very old Loktite laying around in tool boxes around the US. Mine was probably 20 years old and was useless. Bought a fresh tube and the Tech sights worked perfectly and stayed completely tight. So when in doubt, toss it and get a fresh tube.