Went to the gun range this morning testing H322. I decided to try different primers at the same charges to see if there was a difference in velocities and pressure signs.
Note: This was just to establish a baseline and didn’t test for accuracy. I started one grain below the max 6 PPC data for my starting point.
Caliber: 6x6.8 SPC
AR 15 Barrel: 20” BHW (P3) with 1:10 Twist
Brass: Hornady 6.8 SPC once fired brass and necked/sized down to 6mm
Brass trimmed to: 1.680”
Primers: See Below with charge weights and velocities
Bullet: 58 Gr V-Max
COL: 2.230”
Date: 4/30/2024
Weather: Clear Skies @ 70 degrees, Humidity 65% with 2 MPH Wind
Chronograph Used: Garmin Xero C1
Disclaimer: Any information posted by me is meant as information and may not work and be unsafe in your rifle/barrel. Therefore; If you decide to use the information provided then you are doing so at your own risk!!!!!
A 10" drop tube was used in order to get the powder below the neck of the case starting at 29.5 grains.
CCI BR4 Primers and H322 Powder
28 Gr = No Reading
28.5 Gr = 3178 FPS
29 Gr = 3273 FPS
29.5 Gr = 3324 FPS
30 Gr = 3390 FPS
30.5 Gr = 3519 FPS Light Ejector Mark
31 Gr = 3541 FPS Heavy Ejector Mark
CCI 450 Primers and H322 Powder
28 Gr = 3167 FPS
28.5 Gr = 3256 FPS
29 Gr = 3231 FPS
29.5 Gr = 3300 FPS
30 Gr = 3347 FPS
30.5 Gr = 3412 FPS Light Swipe
31 Gr = 3501 FPS Ejector Mark
Federal 205 Primers and H322 Powder
28 Gr = 3143 FPS
28.5 Gr = 3217 FPS
29 Gr = 3255 FPS
29.5 Gr = 3374 FPS
30 Gr = 3373 FPS Starting to see swipes
30.5 Gr = 3397 FPS Light Ejector Mark
31 Gr = 3466 FPS Ejector Mark
I’m currently working on some loads using 55-70 gr bullets in two (2) different AR 10's in 243 so it could be a while before I start posting any group size testing, etc.
