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[ARCHIVED THREAD] - Midlength SBR

Posted: 4/25/2012 3:03:45 AM EDT

Will a midlength gas system on an 11.5" barrel cause issues with short cycling?

Posted: 4/24/2012 7:01:04 PM EDT

[#1]

Quoted:
Will a midlength gas system on an 11.5" barrel cause issues with short cycling?

Well i was told by a gun smith that if i cut my 16 inch mid length barrel into a 14.5 inch it would cause problems with reliability. So to answer your question . Yes correct me if i am wrong.

Posted: 4/24/2012 7:01:53 PM EDT

[#2]

Yes, stay away.

Why would you want to?

Posted: 4/24/2012 7:04:14 PM EDT

[#3]

Ive read that its a very bad combo, 11.5" barrels are way too short for a mid-length. If I remember reading correctly a 11.5" is pretty close to optimal for a carbine length gas system. I'm not a gunsmith, so take that for what its worth. Have you looked at Kino uppers yet? carbine length gas, midlength handguards.

Posted: 4/24/2012 7:12:39 PM EDT

[#4]

Quoted:
Will a midlength gas system on an 11.5" barrel cause issues with short cycling?

Why would you want to run that combo?

Posted: 4/24/2012 7:19:46 PM EDT

[#5]

Isn't a mid length gas block 9" out? Would there even be room for a gas block since the flash hider goes back over the barrel a little bit.

Just get a 11.5" carbine with a longer hand guard.

Posted: 4/24/2012 7:20:13 PM EDT

[#6]

I have a DTI lightweight barrel that is midlength and was thinking about cutting it short for an SBR plan I have and was wondering how it would hold up.

Posted: 4/24/2012 7:27:27 PM EDT

[#7]

The shortest I would go on a mid length is 14.5". But then you could just get a flash hider that makes it over 16" total and get it pinned and welded, then keep the $200.

Posted: 4/24/2012 7:36:25 PM EDT

[#8]

This is what you want:BCM Kino

Posted: 4/24/2012 7:38:26 PM EDT

[#9]

Quoted:
Ive read that its a very bad combo, 11.5" barrels are way too short for a mid-length. If I remember reading correctly a 11.5" is pretty close to optimal for a carbine length gas system. I'm not a gunsmith, so take that for what its worth. Have you looked at Kino uppers yet? carbine length gas, midlength handguards.

IIRC 12.5" is the shortest you should go with a middy.

Posted: 4/24/2012 7:41:25 PM EDT

[#10]

Quoted:

Quoted:
Will a midlength gas system on an 11.5" barrel cause issues with short cycling?

Well i was told by a gun smith that if i cut my 16 inch mid length barrel into a 14.5 inch it would cause problems with reliability. So to answer your question . Yes correct me if i am wrong.

My 14.5" Middy Spike's upper takes offense to that. It runs flawlessly on anything I feed it.

The only issue I could see is your gas tap being too small if you were to just cut it. This is fixed by said gunsmith opening up the hole.

ETA: OP, 11.5" + mid gas is asking for trouble. There would be zero dwell time. Stick with carbine for anything under 14.5"

Posted: 4/24/2012 7:42:12 PM EDT

[#11]

Quoted:
This is what you want:BCM Kino

Yeah, I forgot about the Kino. That would be a great option.

Posted: 4/24/2012 8:20:48 PM EDT

[#12]

Quoted:

I have a DTI lightweight barrel that is midlength and was thinking about cutting it short for an SBR plan I have and was wondering how it would hold up.

Sell and buy a barrel that fits your project. It will cost you less, and be less of a headache

Posted: 4/24/2012 9:19:18 PM EDT

[#13]

You could make it work but you are going to have to open the gas port I would bet. Colt got the 605 to work:

and it had a rifle length gas system. I think it might of had some issues but it ran eventually.

Posted: 4/24/2012 10:32:35 PM EDT

[#14]

Quoted:

Quoted:
Will a midlength gas system on an 11.5" barrel cause issues with short cycling?

Well i was told by a gun smith that if i cut my 16 inch mid length barrel into a 14.5 inch it would cause problems with reliability. So to answer your question . Yes correct me if i am wrong.

My 14.5" Middy Spike's upper takes offense to that. It runs flawlessly on anything I feed it.

The only issue I could see is your gas tap being too small if you were to just cut it. This is fixed by said gunsmith opening up the hole.

ETA: OP, 11.5" + mid gas is asking for trouble. There would be zero dwell time. Stick with carbine for anything under 14.5"

Look like i need to find a better gunsmith.

Posted: 4/24/2012 10:49:53 PM EDT

[#15]

Dwell time. Baah. PUG

Posted: 4/25/2012 1:33:46 PM EDT

[#16]

I took my LaRue 16" midlength gas barrel and cut it to 12.5". It required opening the gas port rather large to get it to run reliably on anything other than XM193. I worked my way up in port size. It is a now a .101 diameter port. It runs well with a standard carbine buffer on everything. When Io run the hot NATO stuff like XM193, I run an H Buffer. So far a little over 1k rounds through it at this new larger port size and no problems. .084" would short stroke about every 3rd round.

But, the dwell time is the issue on shorter barrels. I'm still not sure about the long term reliability of my 12.5" midlength.

Posted: 4/25/2012 1:38:42 PM EDT

[#17]

Yeah a midlength gas system is going to be longer than a 11.5" barrel..... So I say stick with the carbine gas system. Shortest I would go midlength would be a 14.5" barrel.

[ARCHIVED THREAD] - Midlength SBR

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