Loose screws on scope mount rail - Ruger mk II

Dblugil · Oct 16, 2011

I have a ruger mkII stainless model that the scope mount rail keeps comming loose after you fire 20-30 rds thru it. I can tighten them up and it does it again. I have used nail polish and loctite on screws going into receivers before and had 1 problem getting the screw back out. Given the size of the screws it doesnt take much to have a problem. Anybody else have the same issues or use something else???

shayne · Oct 16, 2011

ive had the same issue and used same fix

halmbarte · Oct 16, 2011

How are you cleaning the screws and holes before using the loctite?

H

Dblugil · Oct 16, 2011

rubbing alcohol and q-tips

Straight Shooter · Oct 19, 2011

What is the thread fit like? Are you using an inch pound torque wrench? What are you torquing them to? Loctite or not a fastener needs enough torgue to slightly stretch it and this tension is what actually holds it tight.

Velzey · Oct 19, 2011

Clean the holes and the screws with acetone, apply red loctite (stud type) and enjoy.....

If you ever need to remove them, disassemble the upper and pour almost boiling hot water on the screws and the red loctite will break loose!

Dblugil · Oct 19, 2011

Thanks for the reply

Gunner3456 · Oct 20, 2011

Straight Shooter said:
What is the thread fit like? Are you using an inch pound torque wrench? What are you torquing them to? Loctite or not a fastener needs enough torgue to slightly stretch it and this tension is what actually holds it tight.

Exactly. And if you over tighten the screws, you can permanently over stretch them and ruin the metal. They'll never stay tight.

Gunner3456 · Oct 20, 2011

Dblugil said:
rubbing alcohol and q-tips

One more time. Never rubbing alcohol. It has baby oil in it to replace the skin oils when used, and makes for a lousy cleaner. It's meant only for skin surfaces. Use acetone as Velzey said, or use denatured alcohol which you might have to ask the druggist for. It's still poison, LOL.

Straight Shooter · Oct 20, 2011

Gunner3456 said:
Exactly. And if you over tighten the screws, you can permanently over stretch them and ruin the metal. They'll never stay tight.

Overtorque the screws and it stretches them beyond their elastic range and deforms them in their plastic range. Overtightening can also fracture the threads in the receiver. "ruin the metal." That's why we use a torque wrench.