AR grip install question

[jstrahl]

I'm trying to finish up my latest build and ran into a problem. I'm installing the grip and the bolt will only tighten down maybe a 1/4 of the way before its too tight to go any further. I back it out and the threads on both the receiver and the bolt look good. I also tried an extra grip bolt I had and it doesn't work either. The annodizing has come off the threads as far as it will go in. I've read that it could potentially be that the annodizing got too thick on the threads preventing it from going in any further. The grip is tight enough that it doesn't move, I can't force it off, and the safety works, but I'm hesitant to leave it that way and I don't want to put any power tools to it if I don't have to. It is a brand new Spikes lower that I got a the last 1500. Any thoughts?

 

[Hookeye]

Is the receiver hole tapped all the way through?
Some are, some are not.
If not, then your bolt may be too long. Or the hole's threads need cleaned up.
Easy enough to just run a tap (properly lubed of course) through it.

 

[rvb]

Some grips (magpul, I'm looking at you) come w. Way too much locktite pre-installed on the screws...
-rvb

 

[M67]

Yeah, the pre applied loctite Magpul uses can cause some issues. If you've having issues, it might not hurt running a 1/4-28 tap in the receiver, if you have one.

The other thing is are you sure you're starting the bolt at an angle? Will it thread on without the grip?

 

[Squirt239]

Sounds to me, maybe, it's the wrong thread on the screw. Could be wrong, but I have seen it more than once.

 

[jstrahl]

yes, the hole is tapped all the way through. The second bolt I tried did not have any loctite on it. The bolt is at the correct angle. Also neither bolt will go in without the grip. I'll see if I can find someone with a tap. Thanks for the input so far guys.

 

[rvb]

Also neither bolt will go in without the grip.

That makes no sense. Cross threaded?

-rvb

 

[flashpuppy]

Also neither bolt will go in without the grip.

Careful when tapping. You do it wrong, and you'll also get to learn what a heli-coil is... It sounds that your hole is in fact "screwed up" . A retap will be needed. FWIW, I have successfully made a "chaser tap" by grinding a taper around the first 10-12 threads of another bolt. It'll work in a pinch.

 

[bigcraig]

This happens from time to time.

Variables.
1) Tolerance stacking.
2) Warn tooling.
3) Anodizing.

Add all those things together, and you get a tight hole.(snicker)

Carefully run a tap through the hole. (Turn tap half way, then back a quarter. Continue this procedure until threads a clear.)

 

[Sainte]

mesh the threads of the two bolts together and see if they are the same pitch. after that, take a thread gauge and see what your thread pitch is at inside the rcvr. if this matches the bolts, great. if not, I'd suggest finding a bolt with the correct thread pitch instead of trying to cut new threads.

after that, i's run the tap thru with some light oil as stated above.

 

[1911ly]

yes, the hole is tapped all the way through. The second bolt I tried did not have any loctite on it. The bolt is at the correct angle. Also neither bolt will go in without the grip. I'll see if I can find someone with a tap. Thanks for the input so far guys.

You say the hole is tapped all the way threw. Finding a tap won't help the. Use a tooth pick or something to measure the depth of the whole and compare to the screw.

 

[top hat 45]

if you havent gotten it fixed yet, pm me and we can get it fixed for you. i only live about 20-30 min from you.

 

[zipper89]

You may want to retap the hole with same exact size tap.. Or use a wire brush and take some of the loctite of the screw.

 

[jstrahl]

Thanks for all the replies. Over the weekend I ran a tap through it and that fixed the issue.