AR-15 External Ballistics

**Aguila Blanca** · January 2, 2021, 03:34 AM

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 · January 2, 2021, 04:00 AM

16" ~2950fps
20" ~3100fps

BC 0.304

bfoosh006 · January 16, 2021, 06:48 PM

https://www.ar15.com/forums/AR-15/Va...-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. )

January 2, 2021, 03:34 AM	#1
Aguila Blanca Staff Join Date: September 25, 2008 Location: CONUS Posts: 18,468	AR-15 External Ballistics 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? __________________ NRA Life Member / Certified Instructor NRA Chief RSO / CMP RSO 1911 Certified Armorer Jeepaholic

January 2, 2021, 04:00 AM	#2
greentick Senior Member Join Date: January 15, 2011 Location: Deep South Posts: 261	16" ~2950fps 20" ~3100fps BC 0.304 __________________ nous défions

January 16, 2021, 06:48 PM	#3
bfoosh006 Senior Member Join Date: February 17, 2009 Posts: 1,089	https://www.ar15.com/forums/AR-15/Va...-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. )