Be aware that not all rifles are "magnum capable" rifles. Also not all magnum rifles are the same. Read your manuals and know what the limits of your rifle are. For instance, I have a CVA Staghorn Magnum able to shoot 150 grains of powder. But if you read the manual you learn that means 150 grains of pellets not loose powder. When shooting loose powder they suggest 100 grain loads. Thompson Center and Knight rifles, are able to handle 150 grains of pellets, but again in loose form most of them suggest 120 grains as a max load. Even in brands, the limitations change.
I know what you mean. I was just reading the "Warnings & Instructions" that come with Hodgdon Triple Seven regular 50/50 pellets. It says even though some rifle manufacturers say you can use 3 pellets(150gr), Hodgdon does not recommend it. The limit in their packaging broshure says only use 2 of the 50/50's (regular ones / black box). My manual for my Omega says I can use 3 pellets. But if it is loose 777 instead of Pyrodexthen you have to decrease your maximum 150 gr. load by 15% for the loose powder like you were saying. I will probably only be using 2 50gr. 777 pellets in my Omega. I've found my T/C White Mtn. Carbine and Traditions inline shoot better with about 80-90 grains of loose Pyrodex. Hopefully I can get a good sabot or conical combination with the 777 pellets, I bought 2 boxes of the 50/50's. That would give me 100 shots at 100 grains. What sabots or conicals would you try out first? I have some T/C Superglide Shockwaves (yellow sabot) and some 270 gr. Aero Platinum Powerbelts. Hopefully I will be able to just sight in at 100yrds.
chris