AR15.Com Archives
 Comp won't Fit
glorifiedG  [Team Member]
2/25/2012 9:17:40 PM
I have a barrel with said 5/8 x 24 threads and ordered a comp with the same. Goes on about 3/4 turn and comes to a complete stop. Some pressure with a wrench only does nothing. Thoughts?
Gun_Crank  [Team Member]
2/25/2012 11:25:25 PM
Sounds like the thread pitch is wrong.

Do you have a pitch guage?
hockeysew  [Member]
2/25/2012 11:32:14 PM
You need a thread pitch gauge and mic or verniers. Pitch gauge is self explanatory and measure the OD of the barrel, it should hover around .6250. I don't remember the minor diameter off the top of my head. Figure out what is out of whack and we can figure out a fix.
Do you have an item that is known to have good 5/8 x 24 tpi to check against?
glorifiedG  [Team Member]
2/25/2012 11:33:42 PM
Yes, as in came with an OLD tap-n-die Set I have (says made in Germany, me too) the barrel Looks ok, the comp is a Bit tough to tell, light and angles, and probably not right to check that properly.
Gun_Crank  [Team Member]
2/25/2012 11:41:09 PM
You should be able to tell in the comp just by feel. If it is the right pitch the guage will just drop in. If its say a 5/8-18 it won't feel right at all.

Do you have the proper tap in your set? You could try chasing the threads in the comp.
glorifiedG  [Team Member]
2/26/2012 12:06:35 AM
Originally Posted By Gun_Crank:
You should be able to tell in the comp just by feel. If it is the right pitch the guage will just drop in. If its say a 5/8-18 it won't feel right at all.

Do you have the proper tap in your set? You could try chasing the threads in the comp.


Exactly what I planned on doing when I found this problem. I dont have either, went to 2 local places,they didnt have either, so right now I have nothing to go with. As far as 5/8 x 18, no, from what I can read with the tool I have, its close.I'm a Bit scared to Ape it on.
Gun_Crank  [Team Member]
2/26/2012 1:19:22 PM
Do you know any machinists in your area? Maybe you could borrow one for a couple minutes.
Or order from one of the many tooling supply places. Looks like the tap is about $20 and a threading die is $70, but I only checked mcmastercarr.
AeroE  [Moderator]
2/26/2012 8:35:06 PM
Is this a 1911 barrel?

glorifiedG  [Team Member]
2/27/2012 6:12:58 PM
No its not, Already contacted dealer, they are going to send on that will fit. There were some issues with some, Mine slipped through. Thanks guys