The 30 Carbine 16" is a solid 1800 fps carbine round with the 110gr JRN bullets. It will drop about 100-150 fps depending on powder type. As fate would have it, I have one on the bench for testing our new M1 Carbine magazine so I'll update this with 10" barrel info after testing.
Worked on the M1 Carbine / 357 Mag set ups this weekend after cutting some parts on the newly relocated shop! With the smaller dia of the 30 Carbine getting the follower stack spacing right created a bit of a feed issue. I also need to get my 1.69" oal lengths tweaked a bit. Other than that, mags held 14 rounds of 30 carbine. Will make some adjustments and test with 357 side by side next.