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View Full Version : 14.5" Non-NFA Configurations - Cause for Concern?



Army Chief
22 March 2009, 04:26
A recent discussion thread (http://www.m4carbine.net/showthread.php?t=27592) on M4CN on this topic seemed to elicit some charged -- and not especially civil -- dialogue on the relative merits of the the popular 14.5" non-NFA (permanently-affixed flash suppressor) configuration, as opposed to the baseline 16.1" configuration.

Without recounting all of the particulars, the discussion followed a predictable path ...


- The 14.5" is better because of its improved handling characteristics, and the fact that it offers a true M4 configuration without the NFA complexities, etc.

- The 14.5" is worse because it suffers from velocity loss, and a permanently-installed flash suppressor will prevent you from ever installing a free float rail, etc.

... but things really turned ugly when the topic of cleaning an maintenance.

Some experienced users claimed that regular removal of the flash suppressor is essential on high-round-count weapons because of the potential for pitting, carbon fouling and other residue which accumulates in the gap between the end of the barrel and the mating surface of the flash suppressor.

Others asserted that such fouling -- even in suppressed applications -- was pretty minimal, and unlikely to result in any real problems, provided that the area received a basic level of attention during routine cleaning.

The fact of the matter is that not-every AR owner has the option to go the SBR route, and even then, many simply choose not to so as to avoid the hassles of dealing with a Title 2 weapon. Further, those who might qualify as truly "hard-use" operators tend to have some agency or SOT exemption that eliminates the need for them to even consider a non-NFA 14.5" configuration. We end up with two distinct camps.

Now, I'm not especially interested in revisiting the ballistics arguments and such that go along with any 14.5" v. 16.1" debate: what I am interested in is this notion that a permanently-installed flash suppressor is a recipe for disaster (to over-state things slightly).

Some would disagree, but I doubt seriously whether Noveske would offer this as such a prominent feature on so many of his weapons if it were truly rife with long-term problems. Even if it were, very high-round count weapons that were potentially exhibiting signs of trouble could always have their flash suppressors removed for cleaning and a new one installed (permanent isn't really permanent, but the old flash suppressor will likely be damaged during removal).

It comes to this: for those with NFA 14.5" (or shorter) configurations, how often do you make a habit out of removing the flash suppressor for cleaning (i.e. not just to try out a different type), and how bad is the fouling problem on the crown and threads once the flash suppressor is pulled?

Is this much ado about nothing, or something worthy of collective concern?

AC

Stickman
22 March 2009, 10:08
14.5" barrels have often been looked down on because it was almost impossible to find a decent rail. I can remember during the AWB reading all the complaints where people had a muzzle device permanently attached. The real complaint became about the muzzle device being attached, not about the barrel length itself.

With the advent of the Daniel Defense Omega rail, that doesn't seem to be anywhere near as much of a concern.

The people who want to change out their rail system, or muzzle device on a regular basis are few and far between.


I've read of complaints regarding the Phantom FS, and the internal carbon build up. I've also seen first hand how much can build up inside, and it can be a lot more than you would think. If you think the Phantom is the end all be all of flash suppression, you need to get out more. If you think its a reasonable priced unit that does well, you are correct, but don't expect perfection in any form when you are saying that something is "good enough". Good enough for your uses may be the A1 or A2 FS, for others, its the Phantom, and for others, its the AAC blackout or another open end unit which doesn't have as much build up, and kills flash better.


Regarding the total barrel length, yes, 14.5" is shorter than 16", no matter how you slice it. There are plenty of people who want the 14.5 for looks, there are others who want it for clearing buildings, and at the end of the day, its their weapon, who cares what other people think.


http://stickman.rainierarms.com/galleries/AAC/IMG_1982%201028%20Stick.jpg

Titleist
22 March 2009, 10:59
Also keep in mind with systems like the AAC blackouts you really won't be taking them off, if ever, as the idea is that you apply the rockset to semi-permanently lock them in place to avoid any rotation (to avoid baffle strikes or key-hole issues).

I know in the case of the SBRs I'm building I don't plan on taking the flashhider off once I install the 51-tooth blackouts.

I think Stick makes an excellent point, how often ARE you honestly going to be changing out rail configs?

Army Chief
22 March 2009, 13:03
Those were consistent with my own observations. My admittedly-dated experience as an M-16A1-era armorer was that flash supressors were almost never removed for any reason short of damage -- much less for routine cleaning.

I'm not suggesting that those who would take a contrary view are overtly wrong, but I find little merit in the idea that a permanently-installed Blackout, for example, is likely to become a source of problems over the normal lifespan of the barrel.

The rail issues remain valid, of course, unless you plan go with something the Omega, or use a VIS-based configuration.

AC

5pins
22 March 2009, 15:28
I would think any pitting and fouling would be minimal and easily prevented with proper cleaning. I could see bigger problems with the constant removal and installation of the FS. After all what is the life of a “hard use” barrel? I would think a barrel replacement would come first. Even if it did become severely pitted, so what. It’s not like a critical component that will cause the weapon to quit working.

Stickman
22 March 2009, 16:42
Also keep in mind with systems like the AAC blackouts you really won't be taking them off, if ever, as the idea is that you apply the rockset to semi-permanently lock them in place to avoid any rotation (to avoid baffle strikes or key-hole issues).




AAC also has the non-can version of the blackout.



http://stickman.rainierarms.com/galleries/AAC/IMG_2099%201028%20Stick.jpg

Titleist
22 March 2009, 18:18
If I wasn't running a 'can' I'd rock that same one, Stick.

I find just rubbing the flashhider down with some Hoppes no.9 removes all the carbon build up, and a coat of CLP/SLIP 2000 usually prevents anything major.

So for the life of me I can't think of any real reason you'd be taking the flashhider off and putting it back on repeatedly.

Army Chief
29 March 2009, 04:53
I'm still more than a little surprised at how effective the standard Blackout is, even compared to benchmarks like the Vortex. A casual examination of the geometry involved really doesn't show them to be that different, and yet, the end results are still quite noticeable. Must be some AAC black magic in there someplace.

ACAC

rob_s
29 March 2009, 05:33
I think a lot of people that get concerned with things like cleaning under the flash hider, using KNS pins to prevent "egging" their FCG holes, using an H buffer to prevent "wear and tear on the carbine", etc. are much ado about nothing as a whole. many of the people that get concerned about these things will never put 2000 rounds through that carbine in their LIFETIME. I know that in my own case while, I may have a higher volume of fire than some, I have 4 5.56 carbines that I'm splitting this between making such issues total non-concerns for me.

On the specific subject of 14.5s and their plusses and minusses, I've owned both 16" and 14.5" guns at the same time and never found a difference either way.

TehLlama
29 March 2009, 07:27
Agreed, the people who are overly concerned about this stuff are the same types that build off-road vehicles and then park them in the garage.

I was fully aware of the limitations of permanently attached flash hiders, but as long as the final configuration is known and makes sense, it's not that big of a limitation; the rest is just the muzzle velocity/handling tradeoff that always applies between dissimilar barrel lengths.

I've got a 14.5" and 14.7" Carbine, both fit my needs exceptionally well. On my budget, the drop-in rail systems were more than adequate, so I've had zero complaints.