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View Full Version : Length Difference Between standard 16" bbl. w/ A2 FH -&- 14.5" bbl. w/ extended A2 FH ?



dpast32
23 April 2009, 09:19
Hello Guy's, I guess what I'm really trying to ask is just how much overall length is saved by going to a 14.5" bbl. with a permenantely fixed, extended length A2 style FH, over the "basic" style 16" bbl'd AR15 with an A2 FH. Is it really worth all the effort required for the savings in OAL ? THANK'S in advance for the replies.

Regards, dpast32

rob_s
23 April 2009, 09:23
Less than 1".

I'm actually working on a 3D model to show just this, but it's a ways off.

5pins
23 April 2009, 10:30
Here’s a pick of two Sabre barrels. Top is a 14.5in with a extended A2 FH pined on. Bottom is a standard 16in with A2 FH.


http://generalcartridge.net/images/PICT2817.JPG

Stickman
23 April 2009, 13:19
Hello Guy's, I guess what I'm really trying to ask is just how much overall length is saved by going to a 14.5" bbl. with a permenantely fixed, extended length A2 style FH, over the "basic" style 16" bbl'd AR15 with an A2 FH. Is it really worth all the effort required for the savings in OAL ? THANK'S in advance for the replies.

Regards, dpast32



It depends on what you are looking to do. If you want to go as short as legally possible, without getting into a $200 tax stamp, its the way to go.

There are a lot of people who will complain, and say its pointless. Ignore those people, whats more important is that you understand your own needs for the weapon.

OutlawDon
23 April 2009, 14:00
http://www.ar15.com/forums/topic.html?b=3&f=118&t=435123

http://www.box.net/shared/static/inxrnrnvm6.jpg

dpast32
23 April 2009, 15:17
THANK YOU Guy's, That's Exactly What I Wanted To Know !! I kind of figured it would amount to about an inch of so, but I feel better having the exact data in front of me. I guess if you REALLY have a need to go as short as possible, it just may be wortjh the effort required. But, to loose that just over an inch, you're also giving up 1.5" of velocity & accuracy. And as we all know, the 5.56's performance is all about velocity. ( Re: velocity = fragmentation ) The more velocity at the muzzle, the better it hit's out at the far end. I guess it's like everything else in life, it's a trade off. THANK'S again for all the replies, I really appreciate it.

Regards, dpast32

Ryo
30 April 2009, 23:25
Just to note, one draw back to pinned 14.5 is that you are limited on changes you can do. For example you can't replace the gas block, and can't install certain type of railing systems.

Army Chief
1 May 2009, 01:55
A minor point of clarification is probably in order here. Replacing the gas block, or installing a one-piece free float rail is not impossible if you have a permanently-fixed FS, but it will require removal of the FS, and in most cases where the FS has been blind-pinned and welded, the removal process will destroy the FS.

For this reason, you want to be fairly sure about your end-state configuration prior to directing that a permament installation be done. So long as you are happy with your choices, this becomes something of a non-issue unless you have to remove/replace a gas block or rail because it is damaged. As rare as those cases are, you won't normally be "out of business" here; you'll just have to pay to have your existing FS removed, replaced and (permanently) reinstalled.

Inconvenient and expensive, yes -- but it is certainly possible.

AC

Stickman
1 May 2009, 04:42
ARMS SIR rails

Daniel Defense Omega rails

Midwest Industry rails

Troy Industry rails

Vltor CASV rails



Above are a few of the 2 piece free floating rails that I can think of off the top of my head which will install without problem on a 14.5 w/ permanent FS.

Ryo
1 May 2009, 10:25
A minor point of clarification is probably in order here. Replacing the gas block, or installing a one-piece free float rail is not impossible if you have a permanently-fixed FS, but it will require removal of the FS, and in most cases where the FS has been blind-pinned and welded, the removal process will destroy the FS.

For this reason, you want to be fairly sure about your end-state configuration prior to directing that a permament installation be done. So long as you are happy with your choices, this becomes something of a non-issue unless you have to remove/replace a gas block or rail because it is damaged. As rare as those cases are, you won't normally be "out of business" here; you'll just have to pay to have your existing FS removed, replaced and (permanently) reinstalled.

Inconvenient and expensive, yes -- but it is certainly possible.

AC

Thanks for clarifying it. I should have mentioned that.

Hey Stick.. isn't the DD Omega-X also going to be installable without removing FH?

Stickman
2 May 2009, 10:47
Good question, its possible, but I have not worked with one myself.

TehLlama
2 May 2009, 11:34
I've got a 14.7"/A2 and a 14.5"/Vortex. They're great carbines, and only limited by which rail systems are most practical for them (With the Omega and MRF Rail systems available, it's not very limited at all anymore).

If you're certain of the final layout you want, and especially if you're ordering the completed upper in that arrangement - you'll be extremely happy with a setup like that.

If you're unsure, then there isn't anything wrong with a 16" barrel either. The weight savings isn't very much, and maneuverability is only marginally enhanced.

bigcoastie
2 May 2009, 13:37
Another thing to think about is the velocity of a 14.5" vs the velocity of a 16" while it is minor and most people don't think of it as being an issue many BDCs are calibrated for 14.5" barrels and not 16" barrels