Adding a red dot sight to the pic rail and wasn’t sure what’s the correct amount of torque for the polymer rail? I don’t want to over torque or damage the rail but don’t want the optic falling off either.

What do people use? I assume you also need Loctite 243 blue as well?

Typically 10-20 inch pounds. Likely 15-18. Just use a little common sense and snug well without being stupid about it. Never used any locker but blue would be ok. Even clear fingernail polish will be ok for those small fasteners. Just make sure the optic is shoved fully forward in its slot/slots when fastening. This prevents the item from thrusting forward as the gun moves backward upon ignition.

Trijicon recommended 12 in/lbs and Holosun was 15 in/lbs.

Just snug them up firmly. I use some blue Loctite on the optic to slide/mount screws, but that is up to you.

Polymer mount would not be my choice, but hope it holds up.

The M&P 15-22 is polymer. It’s not my choice. The optic and mount is metal. The pic rail on the rifle is polymer.

I just used the standard 15 in/lbs with blue Loctite 242. Seems to be fine.

I just didn’t want to damage the polymer pic rail.

OH, just snug it up.

Sorry, was referencing the RDO to mount, not the mount to rail.