Scope Mounting: Base Screw Torque

[South Pender]

(I mistakenly posted this in the optics subforum of the Marketplace section. If mods will allow it, I'd like to re-post this here.)

When attaching scope-mount bases to the receiver, how much torque do you put on the screws for a rifle with moderate recoil (like a 270 Win., for example)? Also, do you routinely use blue Loctite on the screws or possibly purple Loctite? Note, I'm not talking about scope-ring screws, only the screws attaching the bases to the receiver, and, in particular 6-48 screws.

 

[Chiquita]

AFAIK, varies based on what manufacturer recommends. But I vaguely remember 50 to 65. As the locktite, Some people do and some don't see the need. IMO, it doesn't hurt if you do.

 

[std7mag]

I use purple loctite on the screws. A couple of drops of green loctite under the base.
A #6 screw i only tighten to 25inlb.

 

[Geezedtee]

2.5nm (22inch pounds) and blue Loctite (non permanent, look on the bottle)

 

[boltfluter]

I use 30 in lbs on the base screws. Really not to critical, just don't brake them off.

Paul

 

[rijndael]

I'd go 18-22 in./lbs and I use blue Loctite. I use it Loctite mostly because I want to keep water out, I shoot in all conditions.

Here's a general torque reference chart for you:

https://www.fastenal.com/content/merch_rules/images/fcom/content-library/Torque-Tension%20Reference%20Guide.pdf

 

[lb-ft]

Blue locktite can create a permanent bond with small screws. Best to use the purple variety special designed & designated for small screw applications.

 

[rijndael]

Blue locktite can create a permanent bond with small screws.

I don't doubt it, but if I find that it won't budge, I just apply heat. Brains and not brawn is usually the best course of action with small fasteners.

 

[hillbill]

25 for molly 6-48 screws
20 for SS, they are softer and break easier.
30 for 8-40