Full-length barrel then. I shot IMR4350 all summer in my 30" Krags using the Hornady "max" of 42.6gr with 180gr bullets with good results. Groups were not as good on hot days (80 degrees or so) but worked well in the 55-70 degree range. Groups also seemed looser in the 40 degree range. Took 3 rounds warmed then in my hand and they shot nearly 6-inches higher. I find that managing ammo & rifle temperature is as important as tweeking the loads. I started several years ago with IMR 4895 in the 37gr range however the load density was poor (shook around in the shell) and the IMR4350 load densities were better.