I started playing with my new Craddock 22” 1/8 twist AR10 yesterday. I pushed the 75gr ELDms pretty hard with H4350. I’m using virgin Peterson brass because they had a bulk sale last spring. I guess I’m a little disappointed in the velocity readings and pressure signs.
From the start of this build I knew I wanted to push it hard and not really care about brass life because this will be a dedicated thermal coyote rig with little concern for reloading the brass multiple times. That being said, I got pretty pronounced ejector marks even down to 42.0gr and around 3350fps. ES and SD wasn’t that great.
I ran it all the way up to 43.6gr and got 3,500fps average and good ES/SD numbers. Accuracy was sub MOA with all loads so I’m not worrying about that. I just don’t know how hard I want to beat everything up. I tuned the gas block down right to reliable last round lock back. I’m running the heavy JP SCS. I started with the light spring and went back to the heavy yellow one.
According to Peterson’s load data, I’m way overpressure. I read through all of these pages and I don’t feel like I’m way out of line. Next weekend I’ll try some loads in the 41gr range and see what it looks like. I’m just surprised I’m having issues getting 3,400fps out of a 22” Creedmoor when I’m getting 3,000fps with my 20” 224 Valkyrie with CFE223 and 75gr ELDms.