11-07-2017, 02:54 PM
Just curious Jaggy13 if you bedded your barrel extension into the upper receiver with blue Loctite or similar substance. I’m a firm believer in bedding the barrel extension and gas block on my AR-15’s. I figure you’ll see between 20 FPS and probably closer to 40 FPS change going from 20” to 18” 6.5 Grendel. The Hornady Black 123 grain ELD-M seems to be a little slower than the previous 123 grain Hornady A-Max factory I chronographed. I used a Magnettospeed and got 2500 FPS to 2510 FPS out of my 20” Shilen with Factory 123 grain A-Max and SST.