AR grip screw length

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deerslayer303

New member
Hey guys,
I assembled two lowers last night sitting on the couch watching TV :D. Anyway I believe there is something awry going on with the grip screw in the PSA LPK's. When fully tight they won't pull the grip flush with the receiver. And There is movement in the grip. Can someone give me a proper length for this screw. I think the supplied screw is too long, that or the threads in the Anderson lowers are a bit too shallow.
 
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tirod

Moderator
A lot of lowers don't have the grip screw threads fully tapped. Some recommend using a tap to chase and clean the threads, others get a shorter screw, and some just bear down and turn it until the grip is tight.

Recommendations usually fall in that order.
 
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rpseraph

New member
I have heard of this happening... generally a problem with the lower. My Anderson lower was fine with a Magpul grip and screw.
 
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greentick

New member
Same problem with an Anderson lower a few days ago. I've built up 3 Anderson's previously without a problem but 2, probably 3 had magpul pistol grips. This last build I just used a standard AR grip I had laying around with a screw from a DSG LPK.
 
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deerslayer303

New member
I am going to measure that screw tonight. I found on the net where the screw is supposed to be 1" in length. I installed the standard grip on these two lowers.
 
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stagpanther

New member
A lot of lowers don't have the grip screw threads fully tapped....
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^^^^this.

No reason to get excited or upset--just get a common tap and finish threading the inside of the grip hole all the wy through --since it's cut at an angle the screw often can go no further even though it has a ways to go before tightening the grip. Take the tap all the way through the hole and problem will be finished forever. You'll also be ready for something like the Jard trigger which uses the grip screw as a means of timing the trigger--quite ingenious. : )
 
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stagpanther

New member
Ok, I'll do that, thank you. That screw is 1/4-28 right?
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I was afraid you'd catch me in a senior moment--I just did one the other day but forget which one LOL. Just use a micrometer I believe the correct tap is a few thousandths under the OD of the screw-- but I believe you have that right. (in other words--I'm too lazy to take a lower grip out to check the proper tap : ) ) Just checked--it is a common 1/4-28" tap.
 
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rem1858

New member
I have two Anderson lowers that I built.
Anderson uses 3/4" length screws.
It is stated on their web site.

Clarence
 
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fourbore

New member
I ran into this too. I used Allen head 3/4 inch with a washer. I was more annoyed by the fact that my LPK, ordered without grip or trigger, so.. no grip screw. I order a Hogue grip and no screw there either. Those 1/4 x 28 not something I have in my screw bin. Actually I did have couple hex head, but no slotted or Allen. Now, after two trips to hardware store, I have spares in 3/4 and 1 inch.

I guess Hogue saves themselves 10 or 20c per unit.

Also, seems odd that since Anderson goes so far as to mention the screw size on the website. I mean why not just tap per spec like everybody else?
 
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rem1858

New member
"Also, seems odd that since Anderson goes so far as to mention the screw size on the website. I mean why not just tap per spec like everybody else?"

Fourbore;

It will be one of those questions that will plague mankind for more than a century.

Just tap it out yourself or use a shorter screw :)
 
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stagpanther

New member
"Also, seems odd that since Anderson goes so far as to mention the screw size on the website. I mean why not just tap per spec like everybody else?"

Fourbore;

It will be one of those questions that will plague mankind for more than a century.

Just tap it out yourself or use a shorter screw
__________________
B.E. Master indoor and out
Distinguished Revolver Badge #99
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It's how the AR parts cartel stays in business. LOL
 
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Ibmikey

New member
The issue on another post quickly became pages of " it ain't mil spec" whines instead of simple alternatives:
1. Shorten the screw
2. Shim the screw
3. Replace screw with a shorter one
4. Buy only LPK with short screws ( most are coming that way now).
5. Tap the hole deeper
6. Buy an assembled lower
By the way no civilian issue AR is completely mil spec.
 
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Quentin2

New member
I've never run into this problem but then I've never used an Anderson lower. Good to know though!

My main issue with the pistol grip screw is using one with a standard slot head so you can use an ordinary flat blade screwdriver instead of having to dig up a hex key that might even be unavailable at the wrong time.
 
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deerslayer303

New member
Why would you ever need to take the grip screw out. Other than to change the grip. I'm sure troops never do it in war time. I'll ask my Dad if he ever took the grip off of his through two tours.
 
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stagpanther

New member
Why would you ever need to take the grip screw out. Other than to change the grip. I'm sure troops never do it in war time. I'll ask my Dad if he ever took the grip off of his through two tours.
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Well, let's see. depending on the fire control group--to change out the group you may very well have to remove the selector. And if you need to remove the selector; you'll need to remove the selector detente pin. And to remove the selector detente pin, you'll need to remove the pin spring. And to do that--you'll need to remove the grip. So there you have it. : )

Which reminds me, how many forum members does it take to screw in a grip?;)
 
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