Recent posts on another web forum claims that the fired 7.62X38 Nagant pistol case needs only shortening to perfectly fit the .310 Cadet chamber. Supposedly PPU is offering new brass for this size as well. This might be worth looking into for those who don't want to spend US$ 1.00 per case for brass that only lasts a few reloadings. I have 2 Cadet rifles, one original and one "rechambered" for .32-20. For the original, I trim .32-20 brass and thin the rim to .045". The altered one needs no brass alterations. I load both with the heeled CBE .320/120 boolits cast from ACWW and lube with LLA or 45-45-10. I never need to resize cases, just de-cap, reprime, add powder (4.5 grains of Unique) thumb start the boolit and shoot. Cases last almost forever and this load shoots to the original sights in my unaltered Cadet. In contrast, my expensive Bertram brass lasted about 5 loadings before cracking.