Black Powder loads.
I know most of you here are highly experienced, but for the novice I thought I'd throw this out there, especially with the all talk of 150 grain magnum loads.
The old 45-70 round used a 45 caliber bullet with 70 grains, yep 70, of black powder. About a 135 years ago, this cartridge (45-70) killed train car loads of buffalo out to 500 yards. A fellow by the name of Billy Dixon once killed an Indian at over 1500 yards. Admittedly this was a "lucky" shot.
Today, I shoot a modern in-line muzzle loader (Thompson Center Encore) that can handle up to three 50 grain pellets. That's over twice the powder used in the old 45-70.
I've settled on two pellets of either Pyrodex or 777 for a total of 100 grains of powder. Now I don't claim to be an expert, but when starting out, don't jump to the 150 grain loads. They'll knock your fillings loose. I know some of the gun shops are selling this guns as Magnums, but start out small and increase to a level that you are proficiant at.
And finally remember, your shooting a black powder gun. It's flight path is like a rainbow. I'm a fairly good shot and don't shoot deer over 125 yards. Again, start out close and practice, practice, practice.
Good Luck!