Ar grip thread pattern

[bbhank]

Hey guys !

I'm helping a buddy of mine put together an a r15.it's a J.d Precision lower. Well the grip screw is really tight. Does anyone know the thread pattern of the screw so I can chase the whole with a tap?
Thanks and merry christmas!!!

 

[Redmanss]

Re: Ar grip thread pattern

I'd suggest calling them direct. I put together my JD Machine lower with a Daniel Defense LPK and the screw threaded in just fine. I'd check on the screw first for correctness before I messed with the lower.

 

[AXEMAN]

Re: Ar grip thread pattern

can you run the screw in without the grip on it to see if its gummed up or if the threads are really bad? might work and save you the hassle

 

[bbhank]

Re: Ar grip thread pattern

The screw threads in perfectly straight, its just very tight. So I thought maybe there was an excess of the coating in the hole. I ran the screw down a couple threads then backed it out, then back down deeper and repeated this process as deep as I could by hand. I pulled the screw out and it looked as good as new. Then i got out a dewalt impact screw gun, which drove the screw about 3/4's of the way in and then It bound up and stopped. I unscrewed again and the screw still looks fine and i put it away for the night hoping to get some insight here and to not mess with it until i broke it. I appreciate any help....

 

[AXEMAN]

Re: Ar grip thread pattern

lol, well lets leave the impact put up for now. someone will chime in, but you dont want to bulge the lower forcing the steel in there or gall it and seize the screw. is it dry? have you tried a few drops of oil? id still worry about forcing it even lubed, but id try it. take the bolt to the hardware store and try it out on the nuts there. ours has a board you can use to find size & pitch. has nuts & bolts glued to it on a graph with sizes.

 

[bbhank]

Re: Ar grip thread pattern

i actually tried two screws with the same result. the first screw i tried was in a JP lower parts kit and the second came with the magpul MIAD grip kit. They bolth feel the same as far as how tight they were. I think I need to just chase the hole with a tap, what do you guys think about doing that?

 

[Redmanss]

Re: Ar grip thread pattern

Google to the rescue:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">SCREW, MACHINE, RIFLE GRIP
NSN: 5305-01-268-1191
Part Number: AN501D416-18

THREAD SERIES DESIGNATOR: UNF
NOMINAL THREAD DIAMETER: 0.250 INCHES
THREAD QUANTITY PER INCH: 28
THREAD LENGTH: 0.992 INCHES MIN AND 1.125 INCHES MAX
FASTENER LENGTH: 1.063 INCHES MIN AND 1.125 INCHES MAX
INTERNAL DRIVE STYLE: B10 SLOT
HEAD STYLE: A33 FILLISTER</div></div>

 

[BERTMAN77MK2]

Re: Ar grip thread pattern

AXEMAN--you are a gentleman and a scholar--I thought this would turn into 1 of the entertaining but uninformitive posts--glad you
saved the day early on---Cheers

 

[bbhank]

Re: Ar grip thread pattern

RED, thanks

 

[Outsydlooknin75]

Re: Ar grip thread pattern

Do yourself a favor, clean all the loctite off the screw .....

 

[bbhank]

Re: Ar grip thread pattern

we chased the threads and it cleaned it out. about 4 full turns we hit a booger once we removed the tap it was perfect...
thanks for all your help