View Full Version : Xm855 muzzle velocity

4 Liberty
08-17-2012, 06:46 PM
With many vendors listing various Muzzle Velocities for the XM855F round, what is the correct figure?........and what is the MV out of an 18" barrel and a 16" barrel? Appreciate your help. I can't get anything out of the Lake City or the Federal webistes.

John S
08-19-2012, 11:27 AM
It's all approximate. Different barrels with show different speeds varying by as much as 100-300 fps. Test barrels usually have enough length to give good results. A reloading manual will generally give you a good idea. As far as the speed given on the side of a box of ammo; it is usually on the generous side.

mike in co
08-19-2012, 06:45 PM
same answer i post the first time you asked...

do not believe there is a mil spec for xm855.......there maybe for m855..that is a mil designation.

the figure is probably difficult to understand. it is probably from a 20 rifle and taken at 78 feet......it maybe from a 16 carbine.....but i doubt it.

one source..not reliable lists 3100fps from a 20"...........quickload says you cannot get to 3100 at the muzzle, much less at 78 ft with out exceeding pressure limits.

my guess is around 3025 with the 78' being 2950 or so from a 20"
from a 16" it drops to 2900 at the muzzle and 2800 at 78 ft...
all guns will vary some...mill is chrome lined battle rifles...
mike in co
(i guess well...midway is selling xm and list vel as 3020 at the muzzle...does not list bbl length..but its got to be 20")