Bushnell Trophy TRS-25 - Keeps Coming Loose

[Captains1911]

This red dot sight keeps coming loose on my Ruger Mark III. I've mounted it twice now using about 20 in-lbs of torque on the mounting screw and with blue Loctite. This last time it was loose after just 10 rds. I'm at a loss as to why it won't stay secure. Any suggestions?

ETA: There are screw marks in the slot of the rail.

 

[Walkalong]

Looks like you need a better rail.

 

[Captains1911]

That's the factory rail that came with the pistol, I guess I'll call Ruger and see what they say

 

[fecmech]

I think I would try to deepen the slots with a round file like a chain saw file. The recoil vibration may be loosening your mount screws. Also 20 in lbs. of torque seems light to me. I've never used a torque wrench in red dot mounts but I personally tighten more than 20 in lbs. Also if your mount screw is dragging in the slot it's BSing your torque wrench

 

[armoredman]

I don't think it's the red dot, sorry, my TRS-25 survived a hundred rounds of 7.62x39mm in my vz-58 just fine, BUT that was the first time shooting it, no definitive word yet.

 

[rcmodel]

Tighten the dang screws.
That is barely finger tight.

Leupold for instance recommends 65 in-lb on their cross-bolt ring screws.

The other thing is, make sure the sight clamp cross-bolt to pushed foreword all the way with hard contact with the cross slot before you tighten them.

That acts as a stop when the gun recoil tries to slip the scope foreword.

rc

 

[Blue68f100]

Completely remove all of the loctite from the screws and holes. Degrease the screws and holes. Blue Loctite works good but you need to let it set over night. And yes you need these screws tight, increase the torque on the screws like rcmodel said.

I have a MKIII with dot sight on mine. It has never loosened up. But prep is needed to ensure a good tight hold. You can move to the red loctite but it should not be needed for a 22.

 

[Captains1911]

The sight was moved all the way forward in the slot, I always do this. The screw was torqued pretty tight, I think the problem is its bottoming out on the rail, fooling me into thinking the sight is mounted tighter than it is. 65 in-lbs is way too much for this screw. I will try filing down the rail slot some, or maybe see if Ruger will send me a new one. Thanks for the suggestions.

 

[dagger dog]

Looking at those slots on the factory rail they look rounded. The Weaver non gunsmith bolt on rail for my MKII Target has square slots and the ring cross bolts are square also.

The Weaver rails are cheap why don't you try one of those?

 

[Captains1911]

Looking at those slots on the factory rail they look rounded. The Weaver non gunsmith bolt on rail for my MKII Target has square slots and the ring cross bolts are square also.

The Weaver rails are cheap why don't you try one of those?

Do you have a link for this rail you speak of?

 

[Captains1911]

Completely remove all of the loctite from the screws and holes. Degrease the screws and holes. Blue Loctite works good but you need to let it set over night. And yes you need these screws tight, increase the torque on the screws like rcmodel said.

I have a MKIII with dot sight on mine. It has never loosened up. But prep is needed to ensure a good tight hold. You can move to the red loctite but it should not be needed for a 22.

How do you recommend removing old loctite from screw holes? For screws I always soak in acetone and then take a Dremmel with a wire brush to it, this gets most of it off. This obviously does not work for screw holes though.

 

[Blue68f100]

I find a small pick works if it's not stuck down tight, most comes loose this way. If stuck use some mek or Carb cleaner to help break it down. They do make some special cleaner for loctite if you can locate it but I have never needed it. For test, what works on the screws will work for the receiver/barrel threads.

If you have a bottom hole tap you can chase the threads to clean them. But most don't have the proper taps size.

 

[Jurist]

My mkiii scopes

I have a MKIII with factory rail which allows me to switch my scopes at will,without ever loosening.The rail does not interfere with the iron sights when the scopes are not in use.I usually start out using my Weaver 2X scope first,then switch to my Red dot Green dot Bushnell and finish the day with iron sights.Never ever have the rings come loose during shooting.I is just a fun setup.The rings are Weaver ,Leupold style Lever Lok.