Another Loose Rear Sight

Finally got my carbine out to the range this morning. Started out shooting nicely, but the more I shot, the worse I got. Eventually I noticed the rear sight was shifted way off to the right, and a little bit of thumb pressure slid it right out of the dovetail.

I searched the forum and found a post from a few weeks ago with the same problem. Although I have a background in machinery & repair, I'm reluctant to give the receiver a whack with a punch. Blue thread lock is cheap, so I do believe I will go that route.

I’ll just throw this out there. When I build a BP pistol/rifle I peen the sight base itself not the dovetail on the barrel.

I was the poster that advised giving it a whack. Maybe a poor choice of words haha. I do that type of “technical peening” in my day job working with extrusion dies (often more expensive than the average Carbine) quite often so it wouldn’t make me too nervous.
I can certainly see the attraction to the thread locker though and would probably also suggest that in hindsight. Most any glue would be reversible with just a bit of heat.

Quote:

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Originally Posted by boomer656

I'm reluctant to give the receiver a whack with a punch. Blue thread lock is cheap, so I do believe I will go that route.

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Brass shim stock is your friend

+1 Blue Loc Tite

First use flat tooth picks to shim it in place, adjust as needed, when hitting where you want it use a pencil to index/mark the top of the dovetails.
Clean any oil off.
Replace rear sight per index marks.

I've used it on 2 carbines I shoot hard. No problems, good tight bond, no problem seeing the Loc Tite.
The Dove tail area doesn't heat up enough to loose the bond.

If you ever need to remove it a hair dryer or heat gun will give off enough heat to break the bond.
Now this is Blue Loc Tite. I have no experience with their other brands.

Quote:

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Originally Posted by rcathey

I was the poster that advised giving it a whack. Maybe a poor choice of words haha....

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Nothing wrong with your guidance/instructions. In my case, I have no frame of reference as to how hard a 'whack' to give it Even if I did, I'm sure my calibration would be off.

Quote:

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Originally Posted by painter777

+1 Blue Loc Tite

First use flat tooth picks to shim it in place, adjust as needed, when hitting where you want it use a pencil to index/mark the top of the dovetails.
Clean any oil off.
Replace rear sight per index marks.

I've used it on 2 carbines I shoot hard. No problems, good tight bond, no problem seeing the Loc Tite.
The Dove tail area doesn't heat up enough to loose the bond.

If you ever need to remove it a hair dryer or heat gun will give off enough heat to break the bond.
Now this is Blue Loc Tite. I have no experience with their other brands.

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I won't need any shims for this. I can press the sight by hand into a very snug fit into what I believe is its original position. Before I put the loctite to it, I'm going to take it out for a few shots to confirm the position is correct. Assuming it is the correct position, I'll clean both surfaces and apply a thin coat of blue loctite. I suspect most of what I apply will be squeezed out when I press the sight in place. A little clean up and it should be a done deal.

Boomer,
Your post brings back a good laugh for me.
Had a rare day at the range with my always busy grown son.
A perfect sunny day, with the range all to ourselves. After pinning up some targets out at 50. I'd shoot a string of 5 carbine rounds and we'd note where they hit. Then he'd use the same carbine and shoot a string of five, again we'd note where they hit. After warming up, we'd use our hits as an average... then fine tune the rear adj site. OK now we're on target, let the games begin. He went first putting all on center in about a 5" circle. When I took over my last couple shots started walking off the target. So I made sight adjustments then handed off to him. Yep his next 5 were back in the 5" circle. When I took over... Again my hits started walking off the target. Re-adjust rear sight, he hits just like his first 2 times. ??? I'm up and again After my 2nd shot I'm flying off paper. After clearing the rifle and thinking to myself that it just isn't my day... I realize the rear sight is sliding off !
It was my sight adjustments that would keep him on for 5. After that 5 it would start moving on me, but I didn't realize it at the time.
To this day he's still bragging about out shooting the ole man.

He got his pay back the next time out. I had used Loc Tite on the sight so that was fixed. Again we did our you shoot 5, I'll shoot 5 to see if sight adjustments were ok.
When we were good to go....... When I hand him the carbine, I'd move the peep up the ramp without him seeing me do so. While he's wondering WTH happened, I'd move the peep back down the ramp without him seeing what I was doing. Did that all day to him and didn't tell him about it until months later when we had Christmas dinner.
Teach him to mess with the 'Ole Man'.

Cheers :cheers:

I didn't have anybody to screw with ..... at least not intentionally. My shots kept moving to the right -- adjust ---- the same, more to the right -- adjust -- the same, more to the right --- adjust --- nothing on the target at all. That's when it finally dawned on me that something other than my eye went seriously south. I didn't think of it at the time, but my target wasn't terribly far away from a gentleman to my right that was being very serious about sighting in his rifle (22 target). I hope I didn't give him a flyer off on the left side of his target to contemplate.

Oh no, Charles you have gotten devious in your old age. You traumatized your poor son for months till Christmas to tell him? I LIKE IT!!!!!!!

The sight is back on .... and good to go. The fix only involved one unplanned trip to the store. I thought I had a tube of blue loctite on hand, but found that what I actually had was a blue tube of red loctite.

I've tightened them up by just peening the edges of the dovetail with the flat end of a ball peen hammer. It works for any dovetail and eliminates having to use a prick punch or Loctite, glue.

Quote:

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Originally Posted by Brian Dick

I've tightened them up by just peening the edges of the dovetail with the flat end of a ball peen hammer. It works for any dovetail and eliminates having to use a prick punch or Loctite, glue.

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Same point I made except one can peen the sight itself and leave the receiver alone. A tiny divot is all that's needed.

If you carefully peen the whole length of the dovetail, it'll last forever. You can stake it again like the military did, preferably in the same spot if it's already been done before. The problem is the receiver dovetail, not the sight.

I agree w previous poster- Blue Locktite.
Clean off sight/ sight base well. I use brake cleaner.
Works.

Thanks to everybody for all the good advice. I've gone with the blue loctite 'solution' to the problem. If it comes loose again, then I'll try one of the other approaches. As it is now, the sight is positioned right on the original stake mark and seems to be working well.

Attachment 93237

Now I just need to spend more time on the range.

With all due respect: peening the entire dovetail is an irreversible undertaking. You bend a piece of steel that may break and you can never go back if the sight breaks or becomes unusable. If you have to take it out, you will beat it out and the new one will have to be hammered in. Fresh Loktite will hold perfectly and can be removed chemically.

No offense taken here. It's simply the correct way to do it and I've done many with no problems over many years. The problem is a loose dovetail and the fix is as old as firearms have been in existence. If you want to glue things, that's your choice but it's not a correct Armorer's repair. You don't need to beat the crap out of it in the process either. "Nuff" said.

I think some do not understand what we are saying about peening the sight base dovetails rather than the receiver dovetails. It is simply standing the sight base up on one end or the other with the 'down' end resting on the pointed edge of the dovetail on an anvil. Then you gently peen the upper edge, flattening it a very small amount. Now when you push it back into the receiver dovetail, it will be tighter. You may have to do it again, depending on how loose it is.
In this way, you are not harming anything, in particular the receiver, and taking the sight back out or simply adjusting it will not be a problem. If you get it too tight, you just take it out and file a tiny bit of the peened steel off.
You are not working on the receiver sight bridge at all, only the base of any of the carbine sights.
Usually this is a VERY SMALL peening that will never be noticed.