AR15 carbine. 5.56mm.
My ‘search-fu’ must be weak and I need this info tonight!
Can someone please help?
Thanks guys!
good luck. i’ve come to the conclusion there is not yet a general consensus for the 12s. i’d pick your favorite manufacturer, and give him a call.
be interesting to see if you get any responses here, though.
As bkb stated I don’t believe that there is a standard. My BCM 11.5" is .076 according to them. My guess is that a 12.5" would be somewhat close.
I roginally said it’s been know to run with the same port size as a 14.5 but then again, that depends what the port size on the chopped 14.5 was to begin with.
Check out these threads. Hope they help.
https://www.m4carbine.net/showthread.php?t=34497
https://www.m4carbine.net/showthread.php?t=63431
http://m4carbine.net/showthread.php?t=18155
.062… but i’d go bigger than that, with a non-suppressed 12.5. with a dedicated suppressed 12.5, that actually seems appropriate. otherwise, the number that comes to mind is as gunz said- .076. it’s the next step up from .073, which is appropriate for 10.5s. the next indexed drill from there is 5/64ths/0781, which sort of seems too big- but who knows.
Yup, youre right. Someone posted a range of .071 - .073 in one of the threads I linked.
Thank you all for the help.
The customer decided on 11.5" and I opened the hole to .076".
Works great.
What is the customary charge for disassembly, shortening and threading and reassembly?
No idea as I do everything myself except for the machine work. I think ADCO charges 75.00 to cut and rethread a barrel.
ADCO charges $65 for cutting and re-threading a barrel and $55 for disassemble/reassemble.