I shoot a .450 Marlin with a 14-inch barrel. I have not used the other powders listed here, but I use RL-7. Use it in my .375 Win also. I like it. Meters well and seems to be a very accurate powder. I shoot a mid-range load of RL-7 in the .450 with 350-grain Hornady Flat Points. I have killed 4-deer with it over the last two years. No problems with retrieval. Hope to get drawn on a KY elk. I sure would like to shake it loose on something a little bigger.