AR-15 External Ballistics

[Aguila Blanca]

A friend of mine is looking for info on zeroing an AR-15 with some XM855 (62-grain) ammo he bought. Does anyone know the muzzle velocity out of a 20-inch and 16-inch barrel, and the ballistic coefficient for M855?

 

[greentick]

16" ~2950fps
20" ~3100fps

BC 0.304

 

[bfoosh006]

https://www.ar15.com/forums/AR-15/Various-Chronograph-results-16-Middie-and-20-Rifle--223-5-56/16-676005/

That link has a ton of velocities from the same 16" and 20" barrel.

His barrel will be slightly different... so YMMV

And as mentioned... about .304 BC ( thats what Trijicon uses. )