AR Grip Screw

[HawkMan]

I have a completed 80% lower I was trying to install a grip and put the grip screw in. The screw wouldn't go the whole way before getting extremely tight.

Looking at it, it doesn't look like it was threaded the whole way and I think because I didn't realize that to begin with that I may have stripped some threads.

Is it normal to have to tap your receiver and make your own threads? I've never seen an 80% lower which had to do that.


Also, any advice? How can I get this grip installed?

UPDATE:

I ended up sawing the screw in half and it seems to hold well.

[Eatmyshade]

That's a pretty common occurrence on 80% lowers. Cut the screw down a bit. Or add washers to the screw to serve as spacers.


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[russ69]

Tap the threads.

[SkyHawk]

Some 100% lowers also come that way. Tap it all the way or use a shorter screw. Magpul grips come with a shorter screw.

[NPFreedom]

How far can you go in? Try the Magpul grips. They come with a much shorter screw.

[GMG]

Find a nut that will fit the screw, screw the nut on and cut off the part of the screw too size. Then remove the nut and it will clean up the threads as you unscrew it.

[CoopsDad]

I had the same issue with one of my 80%s and I just ran a tap through and finished the threading.

[HawkMan]

I had the same issue with one of my 80%s and I just ran a tap through and finished the threading.

What size tap did you use?
Is this the right size?

IRWIN HANSON 1/4" - 28 NF Tap and No. 3 Drill Bit Set, 80232

Also, do I need to drill or just run the tap through?

[HawkMan]

I ended up sawing the screw in half and it seems to hold well.

[Yeti117]

I had the same problem on a 100% lower. I ended up finding a shorter screw at the hardware store for about 20 cents. The thread size is 1/4-28 I believe. Your parts kit likely came with a 1 inch screw, and if you get the 3/4 inch instead it should work perfect.

[SkyHawk]

The tap is $5 and handy to have anyhow. 1/4 x 28

[Half Cocked]

Find a nut that will fit the screw, screw the nut on and cut off the part of the screw too size. Then remove the nut and it will clean up the threads as you unscrew it.

I do something similar whenever I shorten a screw or a bolt only I screw a die onto the bolt before I cut it. After I make the cut I take a file and put a 45 degree chamfer on the end of the bolt before I back off the die and clean the thread profile.

[essjay]

Had that happen on one of my lowers. Using a Magpul screw to install the grip, it would start to cross-thread. Using a stock screw and a BCM screw, it would go in fine. I think the problem is that the Magpul screw is chamfered on the edges, and if you don't have the grip fully seated when you start threading it in, this will cause it to go in at a slight angle.

[xxINKxx]

Just buy a shorter screw or use more washers.

I had a spikes lower that wasn't drilled deep enough. The threads barely went deep at all.... I just stacked some washers and used a shorter grip screw. Never looked back and has been fine for 10 years..