I was lucky enough to buy a big pile of USGI pulldown bullets a few years back. Loading with the "do not deviate from" load of 15 gr of W296 has always worked well in GI or commercial brass in my carbines. For my Ruger Blackhawk in .30 carbine, I wanted a little less "zip" and muzzle blast, so loading half-jacketed 95 & 100 gr bullets with 4227 has worked well for a reduced load. Since that takes a bit of experimenting, I'll let you look up your own data on that from the manuals. I have not tried reduced loads in carbines, and don't think I would recommend it. Always length trim your brass! Carbine brass stretches unpredictably.