M1S 7.5" Barrel? - AR15.COM

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Posted: 1/18/2009 12:52:05 PM EDT

Have any of you used one of these? I know this is a pistol forum but can you give me advice on this length and how to get it reliable? My objective is to build a 7.5" upper (with a tax stamp) for a rifle. I have to have it as near as reliable as possible and I have to make it fit into a space of about 25". From what I've read while searcing the most reliable setup is a CAR tube and a heavy buffer which works well since I have to have a stock.

My biggest question lies in the gas system. Do the M1S barrels come with the gas ports opened up to the propper diameter? What gas tube should I run? Again, I know this is a rifle question in a pistol forum but I figured you all have figured out how to get that size barrel reliable. Thanks

Posted: 1/18/2009 1:24:49 PM EDT

[#1]

I don't have the M1S but I did build a 7.5" using a DPMS barrel. Spikes opened up the gas port for me. Mine runs great now. It didn't before I made a couple changes. I upgraded the extractor with the kit from Bravo Company. Spring, black insert and O-Ring. About $13 for a set of 3. I also run an M16 bolt and carrier, plus a 9mm buffer. I use a CAR tube and spring. It cycles everything including Wolf.

Posted: 1/18/2009 1:55:48 PM EDT

[#2]

What is your gas port diameter?

+1 on the extractror and ring. That's the next upgrade on my list. I run a Heavy buffer and CAR spring as well.

Posted: 1/19/2009 6:48:16 AM EDT

[#3]

Mine runs everything I feed it even on full auto stock from the factory. I have the M1S chrome version.

Posted: 1/19/2009 6:51:05 AM EDT

[#4]

ditto- I've built 3 7.5" pistols over the last year, all work like a charm with whatever I've thrown down range.

Posted: 1/19/2009 3:29:39 PM EDT

[#5]

OK, thanks guys. I just ordered my upper today, but I'm waiting on a reply from M1S about their barrels. It's good to hear that people have some that will run straight out of the box. Thanks again!

Posted: 1/19/2009 4:10:20 PM EDT

[#6]

Did you get the .556 chambered one or the .223 ? The .556 is chrome lined I think.

Posted: 1/19/2009 4:13:11 PM EDT

[#7]

I built an SBR with a M1S 7.5" barrel 1-9 twist non chromelined. I am using a standard carbine buffer. Gas block is the railed one that I bought from M1S with the barrel. I had to add an O ring over the extractor spring for reliable extraction. Before I added the O ring it wouldn't extract about every 5th round. I am also using the standard gas tube they sent. It groups 1.5" at 100 yards.
Make sure you wear earplugs and muffs!

Posted: 1/19/2009 4:33:38 PM EDT

[#8]

I'm going to have to try mine at 100. I was impressed by the accuracy at 50 yards. In the open, I still don't find mine any louder than my 10.5" I'm sure those beside me would disagree.

Posted: 1/19/2009 6:01:21 PM EDT

[#9]

Quoted:
Did you get the .556 chambered one or the .223 ? The .556 is chrome lined I think.

If you were asking me, I ordered just the upper without a barrel. I found a complete CMMG that was in stock and jumped on it. I don't know what the average is, but I noticed there are long waits. I jumped on it while I had the chance. I'm probably going to go with a chrome lined bore and chamber though. I am curious, though, about how long M1S's wait is. I guess it will give me plenty of time to get my stamp.

Posted: 1/19/2009 9:26:10 PM EDT

[#10]

I ordered a barrel and BCG last night and they said it would be about 4 months! I am not in a hurry though as it is for another pistol build that I am in no rush to finish. This will be my first barrel from them though. 7.62x39 (11.5in) should be fun!

Posted: 1/21/2009 3:30:47 PM EDT

[#11]

I just finished a 10.5 inch 7.62x39 build it runs great!!

Paul

Posted: 1/24/2009 9:01:48 AM EDT

[#12]

My M1S 7.5" has never jammed. few hundred rounds so far.
http://www.youtube.com/watch?v=W2Uj55IbN_Y
http://i10.photobucket.com/albums/a125/Idge0/arpistol-1.jpg

Posted: 1/26/2009 8:28:30 PM EDT

[#13]

Mine runs whatever I feed it.

Posted: 1/27/2009 1:37:25 PM EDT

[#14]

I did a 7.5 M1S build 3 years ago and it runs 100%. The added bonus will shoot 1.5" 100 yard groups with Hornady 52 Grain off the bench with Eotech.

Posted: 1/27/2009 2:45:15 PM EDT

[#15]

7.5" M1S upper with Spikes Tactical stripped lower:

Never hiccupped and I use Wolf. Accurate as hell, but I wish I went with a chrome lined chamber and bore. Oh well ... live and learn.

[ARCHIVED THREAD] - M1S 7.5" Barrel?

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