I've also tested a light bullet through the gun... [color:"#800080"]you know, for the recoil sensitive[/color]... at 20 grains, the same 1.1 grain TG load pushes it close to 1300 FPS, but maintains accuracy.
I've also messed with shorter versions of the case
From L-R Ladybug repeater at .625", the same at .500" and then .400".
One of the main reasons I reduced the rim diameter from that of the 25 ACP was to enable feeding through magazines. I haven't finished converting the rifle yet, but the round feeds okay through the magazine of the Remington 581.