We did some load work yesterday with a 375 AM and our 411g Hammer Hunter. We did the first work up with rl33. We reached pressure at 3150 fps and backed down to 3100 fps for a top end load. We decided to them try the Ramshot LRT to see how it would do. We were not able to get to pressure or 3100 fps. It topped out at 3070 fps without pressure and would not gain anymore vel indicating that we ran out of barrel. This was our first try with the LRT but does in this particular cartridge it is definitely slower than rl33.
By the way this big boomer printed a sub .5" 3 shot group at 200y with the rl33. For those who haven't done it, lighting 145g of powder under a 411g bullet launching at 3100 fps is really pretty fun!