02-22-2020, 07:08 PM
With 18" shooting 123gr, I've normally chrono'd factory loads in the mid-high 2400fps range, think 2450-2500fps.
With 20" and 123gr, they're normally 2480-2550fps.
Sometimes there is overlap, depending on the rifling type.
20" is something to consider if you'll be shooting more long range down at lower altitudes, or if you want certain varmint projectiles to retain a little more speed in the closer ranges when hunting coyotes, but this can be addressed with bullet types and BC as well.
I originally wanted a 20" Grendel, and have built and shot a bunch of them, but have felt well-served with 3 different 18" Grendels because I live and shoot at pretty high altitudes as the norm. Since the air is thinner up here, barrel length doesn't matter as much as it does down near sea level.
![[Image: fullsizeoutput_105_zpsgituaykh.jpeg]](https://i1085.photobucket.com/albums/j422/LRRPF52/fullsizeoutput_105_zpsgituaykh.jpeg)
With 20" and 123gr, they're normally 2480-2550fps.
Sometimes there is overlap, depending on the rifling type.
20" is something to consider if you'll be shooting more long range down at lower altitudes, or if you want certain varmint projectiles to retain a little more speed in the closer ranges when hunting coyotes, but this can be addressed with bullet types and BC as well.
I originally wanted a 20" Grendel, and have built and shot a bunch of them, but have felt well-served with 3 different 18" Grendels because I live and shoot at pretty high altitudes as the norm. Since the air is thinner up here, barrel length doesn't matter as much as it does down near sea level.
NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com