11-24-2016, 04:25 AM
Most 20" Grendel AR15s are in the 2500-2590fps range with a 123gr factory load. There are some 18" guns that will do 2500-2520fps with 123gr.
24" guns are usually in the 2600-2675fps range with 123gr factory ammo.
This isn't the first time I've seen this either. I noticed every writer who chrono'd saw some low speeds for a 20", some even in the mid 2300fps range, which is 12.5" barrel territory.
I'm wondering if the lands and grooves aren't providing the same kind of seal we're used to seeing with all the other barrels.
24" guns are usually in the 2600-2675fps range with 123gr factory ammo.
This isn't the first time I've seen this either. I noticed every writer who chrono'd saw some low speeds for a 20", some even in the mid 2300fps range, which is 12.5" barrel territory.
I'm wondering if the lands and grooves aren't providing the same kind of seal we're used to seeing with all the other barrels.
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