To the OP. I've been handloading, shooting and hunting with a .300 RUM for 16 years. Get some 200 grain Accubonds, some slow powders like RL-25, RL-33, maybe some RL-26, and some Retumbo. I think the new slow Enduron powder (7977?) would work well too. The 200 grain Accubond is an absolute killer in the .300 RUM. I'm not sure what Bigjohn is doing, but I doubt his velocities. With the 200 grain Accubond you can expect 3100 to 3200. I have been shooting the same load a long time at 3200. But, like Zeke said, you may need to back off. If you would like to shoot a mono, a friend of mine that has started a new bullet company has verified speeds of 3520 in a .300 RUM with a 181 grain bullet. PM me if you want more info. mtmuley