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Posted: 3/23/2006 6:47:21 AM EDT
I have been reading the thread about 11.5" barrel. Just what was the intention or purpose of the 11.5" barrel? Lots of hoopla plus or minus for that barrel length. So did bushmaster design this barrel for some type of special application?
If one were to have this combination on an a2 upper, are there any negatives for this combination?
Looking at the BM site cannot see a complete carbine offered in 11.5/5.5 suppressor. Might BM have discontinued?
Is it really all that bad? thanks for the responses
Link Posted: 3/23/2006 6:56:07 AM EDT
CQB.

Mike

ps - SBRs are much in use in the sandbox by mercs and security personel as they are quite handy from vehicles and tight quarters......

With the 1/7 twist these rifle can utilize the heavier Mk262 Mod 1 77grn rounds and the 75grn match HPBT rounds with great effect.
Link Posted: 3/23/2006 6:56:46 AM EDT
They were orginally developed for the XM177E2 series of carbines back in vietnam. There was a need for a compact carbine and the 11.5" fit the bill. There is still such a need today and similar length uppers are used for CQB by LEOs and special operations groups.

Since they were the 'cool thing' to have lots of people wanted similar carbines so Colt (and later Bushmaster, Oly, etc) built copies for the civilian demand. People think they look cool (and they do). I'll bet 95% don't give a crap about the terminal ballistics, they just want something that can put holes in paper and LOOKS like the old XM177s. Different strokes and all that. Some guys like the Xm177 type others want 24" bull barrels.
Link Posted: 3/23/2006 6:58:11 AM EDT

Originally Posted By mr_wilson:
...With the 1/7 twist these rifle can utilize the heavier Mk262 Mod 1 77grn rounds and the 75grn match HPBT rounds with great effect.



Yep the tight twist allowing use of heavy OTMs really improves the terminal performance and extend the capabilities of the 11.5" versus using M193 or M855.
Link Posted: 3/23/2006 7:14:51 AM EDT
For serious use, more effective than a 9mm submachine gun, but the same size? BTW, this is a SWAG at best. I don't know the ballistics of a 5.56 from an 11.5" and how they compare to a submachine gun in any caliber.
Link Posted: 3/23/2006 7:18:07 AM EDT

Originally Posted By Unicorn:
For serious use, more effective than a 9mm submachine gun, but the same size? BTW, this is a SWAG at best. I don't know the ballistics of a 5.56 from an 11.5" and how they compare to a submachine gun in any caliber.


A pistol round is a pistol round, a rifle round is a rifle round. Even out of a 11.5" barrel, it will be better than a submachine gun round=pistol round
Link Posted: 3/23/2006 7:18:31 AM EDT

Originally Posted By mr_wilson:
CQB.

Mike

ps - SBRs are much in use in the sandbox by mercs and security personel as they are quite handy from vehicles and tight quarters......

With the 1/7 twist these rifle can utilize the heavier Mk262 Mod 1 77grn rounds and the 75grn match HPBT rounds with great effect.



Mike,


Do you know who sells 11.5" barrels with a 1:7 twist?

Bomber
Link Posted: 3/23/2006 7:30:34 AM EDT

Originally Posted By thebomber:

Do you know who sells 11.5" barrels with a 1:7 twist?

Bomber



I'd call/IM/e-mail this guy first, (he's a good dealer) CMMG.

IM him here at this thread: www.ar15.com/forums/topic.html?b=7&f=118&t=318827

Mike

ps - MSTN and Adco also handle these SBR barrels/uppers
Link Posted: 3/23/2006 7:35:26 AM EDT

Originally Posted By thebomber:
Do you know who sells 11.5" barrels with a 1:7 twist?



Noveskie (sp?) and Colt also sell such barrels.
Link Posted: 3/23/2006 7:39:32 AM EDT
I'm buying one so that when I install a sound suppressor on it I'll have a carbine that is the same basic length as my 16" carbines.
Link Posted: 3/23/2006 7:50:29 AM EDT
[Last Edit: 3/23/2006 7:51:54 AM EDT by Corporal_Chaos]

Originally Posted By thebomber:

Originally Posted By mr_wilson:
CQB.

Mike

ps - SBRs are much in use in the sandbox by mercs and security personel as they are quite handy from vehicles and tight quarters......

With the 1/7 twist these rifle can utilize the heavier Mk262 Mod 1 77grn rounds and the 75grn match HPBT rounds with great effect.



Mike,


Do you know who sells 11.5" barrels with a 1:7 twist?

Bomber



Colt makes them. I think Bushmaster may also do periodic runs of 1/7 twist 11.5" barrel.
Link Posted: 3/23/2006 8:01:12 AM EDT
Thanks for the advise. Where would one buy a Colt 11.5" 1:7 twist barrel?

bomber
Link Posted: 3/23/2006 8:03:44 AM EDT

Originally Posted By thebomber:
Thanks for the advise. Where would one buy a Colt 11.5" 1:7 twist barrel?

bomber



SAW
Link Posted: 3/23/2006 9:03:54 AM EDT
[Last Edit: 3/23/2006 9:08:26 AM EDT by bullyforyou]

Originally Posted By thebomber:

Originally Posted By mr_wilson:
CQB.

Mike

ps - SBRs are much in use in the sandbox by mercs and security personel as they are quite handy from vehicles and tight quarters......

With the 1/7 twist these rifle can utilize the heavier Mk262 Mod 1 77grn rounds and the 75grn match HPBT rounds with great effect.



Mike,


Do you know who sells 11.5" barrels with a 1:7 twist?

Bomber



check the guys at GDS on the EE. very good to deal with, good prices, fast shipping. they always have 1/7 twist bushmaster 11.5"ers. i have 2 and would buy another in a heartbeat.

ETA: http://www.ar15.com/forums/topic.html?b=7&f=22&t=286566
Link Posted: 3/23/2006 1:04:37 PM EDT

Originally Posted By bullyforyou:

Originally Posted By thebomber:

Originally Posted By mr_wilson:
CQB.

Mike

ps - SBRs are much in use in the sandbox by mercs and security personel as they are quite handy from vehicles and tight quarters......

With the 1/7 twist these rifle can utilize the heavier Mk262 Mod 1 77grn rounds and the 75grn match HPBT rounds with great effect.



Mike,


Do you know who sells 11.5" barrels with a 1:7 twist?

Bomber



check the guys at GDS on the EE. very good to deal with, good prices, fast shipping. they always have 1/7 twist bushmaster 11.5"ers. i have 2 and would buy another in a heartbeat.

ETA: http://www.ar15.com/forums/topic.html?b=7&f=22&t=286566





+1 for gds_enterprise


i recieved my 11.5" 1x7 just a few days ago.
Link Posted: 3/23/2006 2:06:11 PM EDT
Can I get a velocity check on 24.1 grns of RE15 and a 77 SMK (or similar load) out of an 11.5?

TIA
Link Posted: 3/23/2006 2:28:53 PM EDT
Why 11.5 instead of 10.5? Just curious how 1" makes that much difference.

BoB
Link Posted: 3/23/2006 2:50:29 PM EDT

Originally Posted By BoB-O:
Why 11.5 instead of 10.5? Just curious how 1" makes that much difference.

BoB


My reasoning is because I want to supress it and most manufacturers won't warranty the can if it is on a 10.5" barrel.

Brian
Link Posted: 3/23/2006 2:56:27 PM EDT
tag.
Link Posted: 3/23/2006 9:41:47 PM EDT
Bushy 1/7 11.5"...around 8000 rounds full auto..no problems...
Link Posted: 3/24/2006 4:26:51 AM EDT
I have an 11.5 ER Shaw 1:9 on my sbr right now. That will be replaced when the Colt 11.5 1:7 arrives next week. I got it off the EE


Bomber
Link Posted: 3/24/2006 4:56:11 AM EDT
I replaced my Bushy 11.5 1/7 with ADCO's EXT SS 1/7 with Wylde chamber. So far so good! (It's running better than the Bushy, but time will tell)

As for reasons behind an 11.5- Yes CQB!

<------ I work in tight quarters and would need a shorter bbl. The 223 penetration is optimal vs. a 9mm/pistol caliber SMG round.
Link Posted: 3/24/2006 5:00:04 AM EDT
Especially on full-auto, the 10.5" barrel is more likely to cause functioning problems, due to the shorter distance between the gas port and the muzzle. A pigtail gas tube might be needed to fix such problems.
Link Posted: 3/24/2006 5:03:03 AM EDT
[Last Edit: 3/24/2006 5:03:51 AM EDT by JoshNC]

Originally Posted By thebomber:
Thanks for the advise. Where would one buy a Colt 11.5" 1:7 twist barrel?

bomber



Edited after I saw you already purchased a Colt 11.5" tube.
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