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AR15.COM
7/23/2025 1:23:15 PM EDT
I own one of the unobtainium Colt AR901-16S rifles, the 901 with the free floating barrel, and I’m trying to do a Colt C20 build. Would anyone happen to know which MLOK rail would closely resemble the one used on the C20?
7/23/2025 1:36:33 PM EDT
[#1]
I believe the more important question would be "is there a forend rail that will fit the AR901 receiver?". IIRC the AR901 is the same upper as the monolithic upper but machined down to take a removable forend. I think the CM762 is made the same way but don't know if it's the same as the AR901.
valheru21:"The argument, "this gun won't go down in value," is used to convince the wife that you are not making a bad financial decision when purchasing a firearm. You're not ACTUALLY supposed to ever sell the gun."
Matt
7/23/2025 2:08:04 PM EDT
[Last Edit: logickl][Edited] [#2]
Quote History
Originally Posted By 1811GNR:
I believe the more important question would be "is there a forend rail that will fit the AR901 receiver?". IIRC the AR901 is the same upper as the monolithic upper but machined down to take a removable forend. I think the CM762 is made the same way but don't know if it's the same as the AR901.
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My 901 doesn’t use the monolithic upper, it’s free floating and has the same handguard used by the Colt Competition models. I believe that handguard is just twisted on.

Edit: realized I read your response wrong, but you’re right. I’m guessing my best shot is getting a M-LOK rail that uses a clamp, just like the handguard used for the CM762/M7.
7/25/2025 10:30:46 AM EDT
[#3]
I’m pretty certain the C20 has a monolithic upper.

I wish we could get it in the US.
7/25/2025 9:11:42 PM EDT
[#4]
https://www.ar15.com/forums/Industry/SP901-LE901-16S-308-Rifle-Picture-Thread-New-TandE-901-M-A-R-C-Modular-rail-page-78/29-199659/?page=40

Discussion of the AR901 starts at post #10.
I clearly have too much spare time.
valheru21:"The argument, "this gun won't go down in value," is used to convince the wife that you are not making a bad financial decision when purchasing a firearm. You're not ACTUALLY supposed to ever sell the gun."
Matt
8/1/2025 6:59:18 PM EDT
[#5]
Quote History
Originally Posted By 1811GNR:
https://www.ar15.com/forums/Industry/SP901-LE901-16S-308-Rifle-Picture-Thread-New-TandE-901-M-A-R-C-Modular-rail-page-78/29-199659/?page=40

Discussion of the AR901 starts at post #10.
I clearly have too much spare time.
View Quote


Thank you for finding that for me. It’s truly unfortunate Colt made the 901 a proprietary firearm.
8/2/2025 11:40:57 PM EDT
[#6]
Quote History
Originally Posted By logickl:


Thank you for finding that for me. It's truly unfortunate Colt made the 901 a proprietary firearm.
View Quote
All AR10's and AR308's aren't proprietary.  There is no spec.  So you saying it's unfortunate seems that you do not understand the platform.  Not a putting your down but just trying to explain what is.

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