I have to get some tools and instead of getting a whole set of T-handles I just need to know the size of allen wrench for taking off the standard grip on an AR.

3/16ths

Thanks!

Quoted: 3/16ths

And a long one at that!  My long 3/16 allen wrench turned up missing, and I ran out to purchase another one to wrap up my lower build!  

Replace it iwith a slotted screw. Everyone should have a screwdriver around, how fast can you scare up a 3/16 allen wrench?

Quoted: Quoted: Replace it iwith a slotted screw. Everyone should have a screwdriver around, how fast can you scare up a 3/16 allen wrench? +1

Colt and FN use slotted screws on the M16/M4 series. for exactly the reason mentioned above.  It's a 1/4x28 (fine) thread, and while the local hardware store may not have the fine thread version, DPMS does.

Interestingly, DPMS is the only major builder of ARs, other than Colt, who is using the slotted screw---unless Bushie or Rock River finally saw the light. Don't know about Conti/Stag though.  They're pretty mil spec on all their other parts, so maybe they also use the right piece.

BTW Happy New Year toall.