I just got my results back for 2 20ga rounds I'm trying to work up. (Thanks to the people at Precision Reloading!)
They both were under powered, and I'm curious if someone could help me in adding a bit more powder. I wanted to work up some light recoiling buck loads.
I am using new Cheddite straight walled hulls. Fiber wad with BPgas seal under it. Cork and felt to bring up the pellets to height, and finally a overshot card and roll crimp.
I am hoping to get the velocity to 1100-1200.
Load 1 1 ounce mixed #F and #1 buckshot 2.75"
16gr Unique
Velocity Ave. 819
Pressure Ave. 6950
Load 2 3/4 ounce mixed #F and #1 buckshot 2.75"
12.6gr Int'l
Velocity Ave. 925
Pressure Ave. 4150
Any suggestions? I just want to tweak it a bit faster--and I have a lot of room in terms of pressure. Are their any rules of thumb as to how much PSI or FPS a grain of powder would deliver?