11-01-2021, 04:23 PM
I dont feel to bad, my estimate was off 32 FPS, close enough for government work. I think the Magnettospeed chronograph produce reliable velocity readings and are pretty easy to use. A Friend has a Magnettospeed chronograph we used to chronograph 16, 18, 20 and 24 6.5 Grendel AR-15s. We got a five shot average of 2619 FPS out of his 24 AA 6.5 Grendel with 31.0 grains CFE223 and CCI 450 primers with 123 grain Nosler CC on a 70 degree day. Ive seen extreme spreads greater than 32 FPS and I probably cant shoot good enough to tell the difference in shot placement with 32 FPS velocity difference, lol. Your SD of 5 is really good and even though CFE223 and LeveRevolution are affected by temperature change I think their burn rate make them very good powders for the 6.5 Grendel.