I had it with Ruger mkIII, rear sight drift problem & fix

[FX-05 Xiuhcoatl]

Ruger MkIII Target models are know for their accuracy and reliability. Unfortunately the rear sight on my handgun will get lose and start drifting after 50-100rds. My 1st mistake was to use blue loctite on the tiny screw, it worked but I forgot to sight it in since I had to pull the sight before applying loctite, my zero was lost...AND....AND... I strip the screw, double

What to do? Order a new sight or pull a MacGiver?

Drill the old screw


Drill, Tap,Thread and enjoy.

[2meterB]

red dot sights are awesome on the mkIII

[FX-05 Xiuhcoatl]

Sorry, I click submit instead of preview post.

[RogerOrange]

I now next to nothing about guns but these screws look very worn out. And thats something I am familiar with. How about replacing the screws and securing them with locktite?
Also if you out of desperation have torqued down the screws the tread inside the gun might be deformed...

[FX-05 Xiuhcoatl]

I now next to nothing about guns but these screws look very worn out. And thats something I am familiar with. How about replacing the screws and securing them with locktite?
Also if you out of desperation have torqued down the screws the tread inside the gun might be deformed...

They are new, snugg with blue loctite. I only spend $5.50 on the tapping die and screws. 400 rds so far and they are holding up.

[tamalpias]

red dot sights are awesome on the mkIII

how would you set up such a rig? I own a mkiii hunter, what are your opinion on sights and mounts?

[Fishslayer]

I now next to nothing about guns but these screws look very worn out. And thats something I am familiar with. How about replacing the screws and securing them with locktite?
Also if you out of desperation have torqued down the screws the tread inside the gun might be deformed...

Yes, that slotted head is boogered but it's just plugging the rail mounting hole.

The screws holding the sight are the Allen heads. My MKII has a similar problem and I might consider FX 05's solution if a 'smith can't fix my dovetail.

[rogervzv]

Blue locktight/threadlocker will solve this problem.

Or a red dot sight will solve this problem:

I have done both on this gun:

[scooter.lincoln]

Just for future reference - blue locktite just needs to be heated to 400 and it will break free. I have to do this at work -a lot! A common hair dryer works

[G21Shooter]

I had the same issue with my MKIII target, I put a shim made from aluminum soda can under the rear sight and it has not budged in 3 years and thousands of rounds.

[FX-05 Xiuhcoatl]

Blue locktight/threadlocker will solve this problem.

Or a red dot sight will solve this problem:

I have done both on this gun:

Nice looking MK, I might just get a primary arms micro just for fun.

[bczrx]

I had the same issue with my MKIII target, I put a shim made from aluminum soda can under the rear sight and it has not budged in 3 years and thousands of rounds.

I had that problem with my 22/45.

I tried blue loctite and it worked loose after about 2000 rounds.

I tried the shim and it started walking also.

I finally solved it the caveman way:


Seriously.

It isn't the 'best' solution, but it worked. If I were a gunsmith I would have had a more refined tool to do it.

I was advised by a few gunsmiths [and Ruger] to use a punch and gently 'tap' the bottom of the sight cut to 'rough' it up by raising little edges and 'thickening' the slot.

I tried this and it wasn't working. Maybe I didn't do it with the right type of punch to drive the surrounding area UP. I found I was driving it down instead.


SO, I did the bubba job.

I turned it over [disassembled, of course] and proceeded to use a punch to tap UP into the sight cut area from below, to cause a bit of a bump in the center of the sight cut. I made measurements to be sure I was only hitting the inside of the receiver at the sight cut area, so that I didn't waste time.

This is not attractive, but it WORKS. The cut was now shallow enough to allow the set screws [without Loctite] to keep the sight from moving over the past 3-4000 rounds.

It is in the top of the inside of the receiver, so that is the area directly above the recoil spring assembly. In other word: not a load bearing surface that affects the bolts smoothness in motion.

After doing this I polished the heck out of the inside to make sure all the edges were smooth as silk so it didn't catch the recoil spring or anything else.

Just don't tap too hard or you can crack the receiver. I didn't, but I know it is a possible problem.


Yep.

I totally jethroed it.

I am NOT a professional gunsmith and would never sell this handgun anyway. However, I am content that there is no structural damage, that there is no impact on the reliability of the action, and that the sight will not move now.

Since even Ruger suggested the hammer/punch combo to tap into the cut [from above] to raise the surface and thicken the cut up, I figured this was not such a weird fix. I just inverted it.

Good luck, whatever solution you use.