It’s even weaker than the 375 Winchester wow! What a huge advancement! LOL The use of flimsy pistol bullets will give it a bad name for lack of penetration same as the 444 marlin. But cheaper for plunking I guess.
30/30 was one of the first smokeless cartridges. Still measured in the black powder method. 30 caliber 30 grains of smokeless powder. 38-55 was an older black powder round 38 caliber 55 grains of black powder.