The .38/55 is another of those rounds that you must handload if you intend to shoot deer with it, because the factory ammo only goes around 1300 FPS with a 255-grain bullet. This is not adequate for deer except under the most favorable of circumstances!! If you hand load it, you can get up to 1800 FPS or so, from a strong rifle like a modern-made M94 Winchester or a strong single-shot. So loaded, the .38/55 gets close to the .375 Winchester in power. (It is an old-time Scheutzen target rifle cartridge, once used in the same rifles as the old .32/40, for 200-yard offhand competition shooting. A VERY ACCURATE load, in the right gun!!)
Keep yore powder dry!!
"Bitte, trinks du das Wasser nicht. Dahin haben die Kuhen gesheissen."