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Posted: 11/18/2008 3:35:49 PM EDT
ok went to put on my new Magpul miad tonight and it wasnt working....tried to use the screw supplied...no go....tried to get old screw in....got maybe 2 turns and then tight.  I think the first couple threads are stripped....if this is the case is it an easy fix?


I bought the lower off a gentleman and I am thinking when he took the ergo grip off and replaced it with the regular style AR grip he fucked something up....my Lower is a LMT


so easy fix for a gun smith?  call LMT?  suggestions?
Link Posted: 11/18/2008 3:37:34 PM EDT
easy fix.  Like any stripped thread, run a tap through it.
Link Posted: 11/18/2008 3:38:15 PM EDT
I would find out what the tread pitch is and buy a plug tap. Another option is to just try and thread the screw itself with out the grip on so you can see for sure what's wrong. Good luck!
Link Posted: 11/18/2008 3:41:57 PM EDT
[Last Edit: 11/18/2008 3:47:58 PM EDT by survivorman]
yea I tried to screw the bolt on without the grip....it got maybe 2 turns and went tight on me....cant get anymore......what is the size screws they use  I think its an A2 AR grip....standard carbine grip.....sorry new to ARs again....I am regularly an AK guy lol   and dont think I would have to deal with this type of shit.....annoying
Link Posted: 11/18/2008 3:45:20 PM EDT
[Last Edit: 11/18/2008 3:45:56 PM EDT by StevesZZ5]
The first couple of threads aren't going to kill it.

That's two out of eleven threads contacting that you're talking about (yes, I just checked one of my stripped lowers for thread contact).

Just clean it up, and you're good to go.
Link Posted: 11/18/2008 3:46:49 PM EDT
Originally Posted By survivorman:
yea I tried to screw the bolt on without the grip....it got maybe 2 turns and went tight on me....cant get anymore......what is the size screws they use  I think its an AR AR grip....standard carbine grip.....sorry new to ARs again....I am regularly an AK guy lol   and dont think I would have to deal with this type of ship.....annoying




Without the grip on you should be able to see if there are any shiney spots or any metal shavings. Could have thread locker in there, which when its dry, the screw has to push that material out of the way. May feel stripped, the screw supplied with most MIAD already have blue thread locker on there. This is what you could be feeling. Chase the thread with a tap. Worse case senario drill and retap.

Post pics, hard to tell without them.
Link Posted: 11/18/2008 3:48:02 PM EDT
Originally Posted By survivorman:
......what is the size screws they use  I think its an A2 AR grip....


It's a 1/4"-28 NF.
Link Posted: 11/18/2008 3:50:43 PM EDT
ok...off hand fellas does anyone know what the diameter size is of the hole  or what tap size I would use?   its an LMT lower if that helps any
Link Posted: 11/18/2008 3:51:04 PM EDT
If the screw won't screw and stay in place with the grip removed, then you don't have any threads left and you probably need to install  or have one of these installed:
http://www.emhart.com/products/helicoil/heliex/design.asp

Wes
Link Posted: 11/18/2008 5:25:14 PM EDT
Originally Posted By Wangstang:
If the screw won't screw and stay in place with the grip removed, then you don't have any threads left and you probably need to install  or have one of these installed:
http://www.emhart.com/products/helicoil/heliex/design.asp

Wes





nope looking down the hole I see plenty of thread left....it looks like its just the first couple threads....
Link Posted: 11/18/2008 5:30:46 PM EDT
You want to use a 1/4"x28 tap to try and salvage the threads, but if the screw was cross-threaded at a weird angle this may not fix it. You might have to use a Heli-Coil or some other thread insert to repair it.
Link Posted: 11/18/2008 5:33:16 PM EDT
Did you confirm the threads are stripped? It might be the red loctite? thats comes on the MIAD screw.
Link Posted: 11/18/2008 7:46:55 PM EDT
[Last Edit: 11/18/2008 7:47:22 PM EDT by docmcb]
Try running the correct size screw or a tap from the top (inside the receiver) down toward the grip if the threads are boogered where the screw starts in the grip end. It will get "on track" where the threads are still undamaged and then straighten out the last few at the end.
Link Posted: 11/18/2008 8:13:29 PM EDT
Originally Posted By docmcb:
Try running the correct size screw or a tap from the top (inside the receiver) down toward the grip if the threads are boogered where the screw starts in the grip end. It will get "on track" where the threads are still undamaged and then straighten out the last few at the end.

+1... thread something in from the top and chase the threads.  Then see if you can get a bolt to thread in from the bottom.

This is why the allen head cap screws are better than straight slotted screws, the straight slot screws are very easy to cross thread into the aluminum lower.
Link Posted: 11/19/2008 2:36:06 PM EDT
guys,   she is all fixed up :)   thanks for all the help and support....I love these boards
Link Posted: 11/19/2008 3:51:10 PM EDT
I would back it out and put some loc-tite on it anyways.
Link Posted: 11/19/2008 4:08:23 PM EDT
[Last Edit: 11/19/2008 4:09:07 PM EDT by PSYWAR1-0]
Originally Posted By Gamma762:
Originally Posted By docmcb:
Try running the correct size screw or a tap from the top (inside the receiver) down toward the grip if the threads are boogered where the screw starts in the grip end. It will get "on track" where the threads are still undamaged and then straighten out the last few at the end.

+1... thread something in from the top and chase the threads.  Then see if you can get a bolt to thread in from the bottom.

This is why the allen head cap screws are better than straight slotted screws, the straight slot screws are very easy to cross thread into the aluminum lower.


I have to disagree, Allen Head screws are way too easy to overtorque to the point that the star washer becomes part of the grip, and ceases to function as it should.  

Ive seen low quality grip kits that had way too long grip screws that ended up binding up the trigger, impacted  star washers, broken ears, pinched detent springs ect all because folks just can not be happy with an A2 Grip or instead of taking it to a trained and qualified individual to get one of these grips installed, go all WECSOG on the thing and ruin the lower



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