My Iron Sights I purchased from Troy Industries have arrived and i will be installing them on my S&W M&P 15 ORC. I have a question regarding which strength of loctite to use.....

My front sight will be housed on top of the picatinny-railed gas block and will likely get very hot. that being said, i don't want to go to the trouble of purchasing/applying a strength of loctite that will loosen when hot and do me no good. on the other hand, i'm not crazy about the idea of permanently locking my sight in place forever should i want to adjust &/or remove it someday. does anyone have advice on what strength of loctite to use for the front sight with these issues in mind?

should i just use the same strength for the rear sight even though it probably will not have the same heat issues as the front? or should i go to the expense of purchasing a different strength for it? does it matter?

any advice on this will be greatly appreciated. Thanks in advance!

p.s. - i'm not trying to save money on loctite. i want to do what is best for the life of my gun with the full intent of keeping these iron sights locked in place without constantly fiddling with them unless at some point in time i decide to move them. i dont plan on moving them but you never know...

Try it without first. You can always use blue Locktite later if you really need it. Just remember that it's very hard to remove all of it from the threads.

I simply can't imagine using thread locker on iron sights on an AR. The whole reason for the Picatinny rail is to be able to easily add or remove accessories as needed. I have 1500+ rounds through an M&P15A and neither the BUIS or the red dot have loosened.

Blue thread locker = vibration resistance, still removable.

Red thread locker = the equivalent of thread super-glue, will take heat and force to break loose.

I use blue thread lock on my AR's, and have no issues.

Don't forget green . Put a drop on something all ready installed and it creeps in to the threads to lock it down.

I use blue for my rifle's w/o a problem and I have had to remove some gear that had it on w/o problems also.

Blue. I went without when I added an iron sight on my OR gas block. It was basically falling off by the time I got home.

I installed my sights without any Loctite. That was 9 months...and countless magazines... ago and they are still tight. My EOTech HWS sight is made to be removable so I didn't use any there either. Try your gun without it first, you can always use it if needed.

Be careful when ever using loctite on optics or BUIS threads. Once I used it on a red dot scope mount and I torxed it down a little too tight. Well when I tried to remove it I snapped off the bolt head and ruined the red dot optic, but that was my dumb a** mistake shame on me.

This should help anyone decide what threadlocker to use. Threadlocking Solutions Guide

Troy sights come with blue loctite already on the threads. At least mine did. They have never loosened on me. Avoid using red on anything you could bend, scar or otherwise aren't willing to mangle.

My Magpul MBUS that I put on my 15-22 came with it also.

On a gas block? That's what I find to be the reasoning. Heavy vibration from being staked to the barrel and high heat swings...

Agreed though. Not hurting anything by mounting it without first.