User Panel
User Panel
User Panel
|
Posted: 1/19/2024 12:52:12 PM EDT
I’m building a Colt 9mm AR and it will be a SBR, my question is on the barrel, I know the 16” barrel models use a thread pattern of 1/2x36, but do the 10” barrel models use the 1/2x28 or 1/2x36? I want to use my 9mm 1/2x28 direct thread on suppressor on it and obviously the 1/2x36 will not work, and having 10” barrel retreaded correctly with the front sight post may not work and won’t look original, where if I got a 16” barrel and have ot shortened and threaded it would what I want.
Thanks |
|
|
|
MN, USA
|
Posted: 1/19/2024 1:38:12 PM EDT
[#1]
I doubt they would use a different thread on the longer barrel. Those processes are pretty much SOP.
|
|
|
|
Posted: 1/19/2024 1:42:39 PM EDT
[#2]
If you're building it, what/who's barrel are you using? The manufacturer should state what the thread is, and there's lots of options for 9mm AR barrels to choose from to get what you want.
|
|
|
|
MN, USA
|
Posted: 1/19/2024 1:54:54 PM EDT
[#3]
Quote HistoryOriginally Posted By D_Man: If you're building it, what/who's barrel are you using? The manufacturer should state what the thread is, and there's lots of options for 9mm AR barrels to choose from to get what you want. He said Colt. |
|
|
|
Posted: 1/19/2024 1:57:22 PM EDT
[Last Edit: D_Man]
[#4]
Quote HistoryOriginally Posted By s4s4u: He said Colt. If it's a Colt barrel, I assume their 10.5" upper then. IIRC, all Colt 9mm barrels are threaded 1/2x36. |
|
|
|
|
Posted: 1/19/2024 1:57:57 PM EDT
[#5]
Quote HistoryOriginally Posted By s4s4u: He said Colt. Quote HistoryOriginally Posted By s4s4u: Originally Posted By D_Man: If you're building it, what/who's barrel are you using? The manufacturer should state what the thread is, and there's lots of options for 9mm AR barrels to choose from to get what you want. He said Colt. Building a classic Colt 9mm sub gun clone. The new lowers having the selector stops left intact just scream 9 mm sub clone. |
|
|
|
|
Posted: 1/19/2024 1:59:59 PM EDT
[Last Edit: mstennes]
[#6]
Quote HistoryOriginally Posted By s4s4u: I doubt they would use a different thread on the longer barrel. Those processes are pretty much SOP. Yes, but we are dealing with Colt and we see how they do and have done semi autos in the past verse the M series select fires. I have a reached and searched and have yet to find the thread pattern for the SMG 10” barrel. |
|
|
|
MN, USA
|
Posted: 1/19/2024 2:32:46 PM EDT
[#7]
Quote HistoryOriginally Posted By mstennes: Yes, but we are dealing with Colt and we see how they do and have done semi autos in the past verse the M series select fires. I have a reached and searched and have yet to find the thread pattern for the SMG 10” barrel. Quote HistoryOriginally Posted By mstennes: Yes, but we are dealing with Colt and we see how they do and have done semi autos in the past verse the M series select fires. I have a reached and searched and have yet to find the thread pattern for the SMG 10” barrel. From the archives, looks like it is 1/2-36 The RRA is 1/10 twist just like the Colt. Both have 1/2-36 muzzle threads. |
|
|
FL, USA
|
Posted: 1/19/2024 3:05:47 PM EDT
[Last Edit: amphibian]
[#8]
I did this for my DoE clone build..
Somewhat of a retro look using A1 FH and then thread pitch don't matter....also no concern of can coming loose. My setup isn't clone correct and I don't care since I want to run suppressed but for your 10" Colt upper a FH would look right.  |
|
|
|
Posted: 1/19/2024 5:53:33 PM EDT
[Last Edit: mstennes]
[#9]
Quote HistoryQuote HistoryOriginally Posted By s4s4u: Originally Posted By mstennes: Yes, but we are dealing with Colt and we see how they do and have done semi autos in the past verse the M series select fires. I have a reached and searched and have yet to find the thread pattern for the SMG 10” barrel. From the archives, looks like it is 1/2-36 The RRA is 1/10 twist just like the Colt. Both have 1/2-36 muzzle threads. I kinda of wondered, looks like a 16” than shortening it to 10” is the only avenue to obtain the desired look for a 635. It will require a drilled out M16 flash hider as well but that’s easy. ETA, what I thinking about is the R0991 which has a 10.5” barrel, which is what I want build. |
|
|
|
|
Posted: 1/19/2024 5:55:59 PM EDT
[#10]
Quote HistoryOriginally Posted By amphibian: I did this for my DoE clone build.. Somewhat of a retro look using A1 FH and then thread pitch don't matter....also no concern of can coming loose. My setup isn't clone correct and I don't care since I want to run suppressed but for your 10" Colt upper a FH would look right. https://c3junkie.com/wp-content/uploads/2023/12/DoE-Modern1.jpg That thing is sweet! Looks great! I thought about doing a DOE but decided 635 but do a flat top then have the removable carry handle sigh as well as a KAC RAS for attaching a light. |
|
|
|
IN, USA
|
Posted: 1/23/2024 10:32:53 PM EDT
[#11]
Way back when Colt was the only game in town all their 9mm barrels were 1/2x36. That was the standard for all AR 9mm barrels.
That is so you wouldn't put a too small of muzzle device on your 9mm barrel. Then when suppressors became more popular, some barrel manufactures started to thread 9mm barrels in 1/2x28 so they could share a suppressor for different calibers. That is why you need to make sure of bore size on your muzzle device. |
|
|
USA
|
Posted: 1/26/2024 11:32:15 AM EDT
[#12]
Alot of manufacturers threaded 9mm 1/2x36 so that someone wouldn't try pushing a 9mm bullet through a 5.56 flash hider. Liability issues.
|
|
|
|
Posted: 1/31/2024 9:43:41 PM EDT
[#13]
I have 16 inch 1/2 x 28 barrels on the shelf currently.....stock is again low...but running more.....
|
|
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
