Hey guys, I am about to assemble my first rifle by myself, and am wondering what everyone would consider essential threads to have Blue loctite on them?
Castle Nut/Buffer Tube?
MIAD Grip screw?
BUIS (Daniel Defense front and rear)?
Yea or Nay? Any I’m leaving out?
Not an expert but for what you have listed, this is what I did:
Nay - Castle Nut/Buffer Tube? It should be staked.
Yea - MIAD Grip screw?
Yea - BUIS (Daniel Defense front and rear)?
.
As long as the castle nut is properly staked, it’s not going to back off on you. The MIAD grip screw has nylon in the threads, so that’s not backing out. You could possibly use a little bit of blue loctite on the BUIS. I’m not familiar with DD’s BUIS. If they use nylon on the threads, you should be ok without loctite.
As someone who had to machine the buffer retainer out to get the buffer to work, I would say… DO NOT Loctite anything. I thought it would keep the receiver extenion tight, but it ran down into the well and the spring and retainer would not move at all ergo machine shop time.
could you not have just heated it?
I would loctite anything you don’t want to re-tighten or check after each range visit. If it isn’t staked, and has threads, it gets loctite on my rifles. Well except for the mag catch and barrel nut. Just off hand the stuff I have loctited are grips screw, ambi-safety, front and rear BUIS, MI FF rail, red dot mount screws, weaponlight mount screws, and I think thats it. My muzzle device is held on with a crush washer, RE castle nut and BC screws are staked, and like I mentioned the mag catch isn’t going to loosen. I use anti-seize on the barrel nut though.
I’ve been to a loctite seminar, we use a lot in my industry, and one of the things they mentioned is most people use way too much. It’s good for them as that stuff isn’t cheap and the more you use the more you need to buy from them. But, bad in cases like drrufo mentioned. A drop or two is more than enough for the type of loctite recommended and size of screws on an AR. No need to drench the threads with it. I would recommend blue 243 on most screws and red 271 wherever you need to be absolutely sure the screws don’t back out. The 271 does need to be heated above 500°F if you want to get the screw back out so keep that in mind if you use it.
I loctite my buis and optic mounts.
A properly manufactured and assembled base unit does not need loctite anywhere, except for add-on accessories (rails, grips, mounts, etc).
I used blue loctite on add ons only: attaching my H1 to my LT660, attaching rails to my MOE HG, rail accesories.
My Buis, grip screw, and rails.
I make it a practice to loctite everything with a thread that I don’t want coming loose.
Cameron
I had to tighten the MIAD on my REPR today for the first time in over 2500 rounds. Granted, I’ve never had that happen on any other ARs, but it gave me the idea of a little blue loctite. I’m still mulling it over in my mind…
+1 Quoted for truth
This is what I do. About the only threads I don’t loctite are things that are staked. I use only blue loctite in an AR build.