I've been torn on a configuration for my first build.  So I have a couple of questions:

1.  Given that I'm limited to 16" as the minimum barrel length, is a 16" carbine setup even worth it in terms of being practical as a CQB weapon?  If it is, is it worth the loss of real estate that i might need at the handguard as well as a decrease in long range accuracy?

2.  I've decided against building an ar-15 for long distance shooting.  It seems to me that there are better calibers for long distance shooting.

So my indecision is basically, what configuration would be the best compromise or would best fit what the ar-15 was intended for?

I find a carbine with an A-1 stock to be much handier than a 20" AR.  I don't see any need for more handguard space, but if you do, you can get a dissapator upper nad have you're full-lenght handguards on a 16" barrel.  Of course, it'll be ugly as sin.

And don't forget, if the AWB goes away next year, you'll be able to put a collapsible stock on it.

16" is fine for a carbine. The colt M4 MT is the best deal around because it is pre decked out. In another 6 months the rage will be A4s. It will be like when everyone freaked with the M4gery. A4gery is the future.

The A1 rifle is the true gene design. It is the best setup. IMHO.
GG

I thought about a dissipator but the bushmaster dissipator barrel cannot accept freefloating handguards because of it's gas system design.  Gun guru, sorry if I sound ignorant, but what is the difference between an a4 and an m4?

as for the fading of the awb, I don't put much faith in our politicians looking out for our best interest at times.  I'm crossing my fingers that I'm wrong.

So if anyone knows a dissipator setup that will take an aftermarket handguard, let me know.

A4 is a 20" gun with a flat top. Marine Corps

M4 is 14.5". Used by the Army

thanks appreciate it.  Another company has to make a dissapator setup for the ar-15 that allows for aftermarket handguards.

I just put together a FT Carbine last month. A1 stock, M4 handguards, #40 arms. and an EoTech. Makes for a great handling little arm. Only mistake I made was I installed a 20"LW barrel on the leftover A2 upper. Now that 16" barrel feels like a brick is hanging off the muzzle. I'll be sending it to KKF soon to get it cut to an A2 profile. I could get an M4 barrel, but it just doesn't look right without a collapsable stock. A carbine looks acceptable with the A1 stock...Barely. ;)

If I had to do it over again I would have bought the Bushy carbine with the patrolman's(16" M4 profile WO/brake) or superlight 16"(A1 profile) barrels.

As for the carbine vs. rifle sight radius I find I have problems with the carbine at +50 yds. Thats well over CQB ranges. I can however keep the groups to 3"-4" center mass at 100 yds.

genius91

Where do you get that generalization?  Many Army units have had the A4 for a while like the 4ID and even National guards units have them.

I have also seen pictures of Marines with M4's.

We have thw M16A4's with Comp M's.  

It can't accept the Bushmaster free float tube - it [b]CAN[/b] use the Houge free float tube (which Bushy also sells and will install for you if you buy the upper direct from them).

I'd bet there is a FF RAS or RAS II in 20" length (or a SIR in that length soon). They should be able to handle the Dissapator.


The M4 is a carbine - 14.5" barrel and telescoping stock.  Much handier and more useful IMHO.  Most are flattop (early versions had the M16A2's carry handle)

The M16A4 is the flattop version of the M16A2.  20" barrel, flattop receiver (better for optics) and the fixed A2 buttstock.

IMHO the 16" is the most practical AR length for most people.

It works fine for CQB (especially if you are using the shorter Stubby or Sully stocks).

Also, DPMS will make you a 16"-barreled-upper with a rifle-length FFHG and sight-radius.  They won't call it a "Dissipator" because that is Bushmaster terminology, but that's basically what you'll have.  I have BM pre- and post-ban Dissipators and a post-ban DPMS equivalent set-up - they are all fine weapons and I am quite partial to this configuration.  Not everyone agrees (e.g., JohnTheTexican above).

Slap an LE stock on that 16" carbine, and it will me short enough to do any CQB stuff you need.  

As far as accuracy out of a 16" barrel, you're not giving up too much in practical terms...under 300 yards.  If you need something past that, then, yes, another rifle might be better...like an AR10 lol.  

BTW, I had my 16" Model 1 gun out again, and it's still shooting 1 1/4" groups regularly with 55fmj Hornady "blemished" bullets...and there were 2 sub moa groups in there, and a couple at 1".

At 300 yards, that's still gonna put the rounds where you need 'em...how accurate do you need to be?  

A postban carbine is much handier than a postban rifle and half the cost of a preban carbine.  It's more accurate and more powerful than a handgun.  Get an A1 or shorter stock and it will be handier.  You aren't giving up any theoretical accuracy with the shorty.  

The rifle you are describing is the gun I wish  I could buy, and I'm looking for the money to convert two of mine to that config: 16" with full length tubes.
Wes at MSTN has talked with me about it: replace the front sight with a low profile gas block and put a folding sight further out.  Maybe he has some other options for you.