Team.
I have an experimental rig from Charlie for making .22 gas checks. Tried it out today at 50/55y in my Rem 700 .223 pushing the Lyman 225462 over 6gr of Green Dot for 1700fps; a proven load. I shot Freechex in 0.005 Cu and 0.0043 soda can wall plus old style Lyman brass slip on checks and current Hornady crimp on.
Here is how it they went. The Freechex, flyer not withstanding on the Al target shot into 3/4 inch.
I think the Hornady group may have been subject to a neck tension issue. Can't explain the flyer in the Al group. Retesting tomorrow weather permitting.
All in all, really happy with the results. The Freechex anvil supplied takes 5/16 disc however these makes checks with sides a shade too tall for the likes of the Lyman 225415. On the 25462 they are fine. I have suggested to Charlie he use 9/32 punches and adjust the anvils to suit which he is going to do.