Mk III Competition rear sight tightness

[ozzie]

After the first 15 rounds the grouping is becoming larger and even more and more scattered. All my friends told me that I was getting tired or developed eye strain. That was not difficult to accept, I am 81 years old. However, this is not my normal performance, the gun was shooting very tight groups previously so, I decided to check the rear sight. Lo and behold, the little grub screw was not tightened fully. Because of the difference between the length of the dovetail and the width of the sight body, the sight was slightly over to the right of the receiver in order to get the grub screw over the flat of the dovetail, consequently the windage blade had to be adjusted over to the left to get it central.

The sight body seems solid in the dovetail, I did not try to move it with a punch and hammer. I have tightened and Loctited the grub screw as tight as I could but it is half off the flat land of the dovetail. I can hardly wait to try it and see if it fixed the grouping problem.

My question is, has anyone had a similar experience with the Mk I, II or III target model?

 

[ACM73]

EXACT same problem with my mk-iii competition. I drifted the sight over to the right to center it up, then re-sighted in and it was fine for a while, then all of a sudden it moved again. I drifted it back and tightened the screw and loctited it. It hasn't moved since then and I have taken it out and shot it maybe 5 times or so since then. I'm not convinced that it wont shift again, but I'm not sure what else to do. The screw doesn't seem to do anything to keep it in place, seems like its just staying in place from the tightness of the dovetail. I hope someone has some advice for ya because I could use it as well.

 

[ozzie]

If it moves again, the next thing I am going to do is, take the sight off, clean the dovetail and re-fit it with Loctite 263, the red, non break variety in the dovetail. As you say, the screw does not do anything because there is nothing for it to bite into, except fresh air.

I might write to Ruger about this.

I'll let you know what comes out of all this.

 

[ACM73]

I considered putting some loctite underneath the site, but I keep toying with the idea of mounting a red dot on the gun in the future and I'm worried I wouldn't be able to get the sight off to do that. I may try it if it doesn't stay put this time though, probably with the blue loctite though. Let me know how it works for you!

 

[ozzie]

You would not have to take off the iron sight to fit a red dot, the Weaver rail just fits in front of it, I've tried it. I am just thinking, the blue Loctite might shake loose, red Loctite would lock it firmly, the screw would become superfluous. I wonder what would happen to polished stainless steel if I heated it to 250 degrees to break the loctite joint. Probably become discoloured permanently.

 

[ACM73]

I like the dovetail mount for the burris fastfire, it looks a lot cleaner in my opinion so I would go with that if I got one, that's why I would be nervous about the loctite.

Well, if you plan on keeping the rear site on for good then you shouldn't have to worry about breaking the joint or discoloring the steel!

 

[ozzie]

Well, after about 200 rounds following the tightening of the set screw, the groups are consistently tight and it looks like the rear sight is solid as a rock. Problem solved.

 

[ACM73]

Good to hear!