It seems that shorter barrels are best for urban settings. Are the 16'' barrels short enough, or should I opt for a 14.5'' or maybe 11.5''? With carbines as short as they are (esp. with non-fixed telescoping stocks which we will hopefully get back next year), is anything shorther than 16'' really beneficial? What is the difference in ballistics?

[url]www.ammo-oracle.com[/url]

The minimum length for a barrel before you need a $200 tax stamp for a SBR is 16" so the shortest you can get is 14.5" with a muzzle attachment which brings it back to 16"

Are you going to spend the money for a SBR?

[img]http://www.bushmaster.com/images/faqchart.gif[/img]

FWIW, I opted for the 16" over the 14.5 or 11.5 w/ permanently attached MBs for the increased "frag" range of M193..., see here:

Barrel Length vs. Velocity & Fragmentation -

Barrel..................Muzzle.Velocity............Fragmentation.Range
Length................M193........M855...............M193........M855
(in).....................(fps)...........(fps).............(yards)......(yards)
20.....................3259...........3100............135/190.......125/190
16.....................3132...........2989............105/160.........90/155
14.5..................3064...........2970.............90/145..........85/150
11.5..................2872...........2738.............45/95............10/75

Frag Range: Maximum range, in yards, for rounds to fragment.
First value is the distance at which bullets are at 2700 fps,
Second value is the distance where the bullet is at 2500 fps.
(Fragmentation ranges assume 59.6
degrees Fahrenheit (and 29.92 "/Hg), higher tempertures will extend the ranges slightly.)

To reliably fragment, military FMJ rounds must have a velocity of 2700fps;
Velocities under 2500fps rounds will not fragment.


Mike

I agree with mr. wilson.  16' bbl length is the minimum on my ARs.

Bud

On a post ban perhaps but I am not willing to tote a 17.5" barreled AR in close confines.  Also if you go to the 75 and 77 grain ammo the 14.5" barrel out performs the 16" barrel using M193.

Alright, guys. 16'' it is. Thanks!