RE: .45 cal ?
If you already purchased the .45 caliber it is kind of a mute point as to the advantages or disadvantages.
It used to be they were hard to tune and develop a loadbecause of the barrel twist rates. And because of that people avoided them like crazy. Then some of the companies started to come around and put a better twist rate to them and the .45 because a very accurate rifle.
Also it used to be hard to find projectiles for the .45 caliber. That is not the case anymore. Most of the stores carry a good selection of .45 caliber bullets.
Disadvantages.. the idea they shoot flatter ??? OK I will give them that. Is it going to make a big difference. Well if you were shooting 150-200 yards all the time at deer size game, there might be a little advantage. BUT anything a .45 can do, the .50 caliber can match. No matter what range you want to shoot. And if I were hunting moose or elk size game with sabots, I would want a .50 caliber no matter what range I was shooting.
.50 calibers still have a better selection of bullets, sabots, and conicals most of the time. Get to the middle of no where on a hunting trip in small town USA and forget your bullets. Go to the local wal mart or small sports shop and see what they carry for your rifle? Here you would be hoping you had a .50 caliber.
A .50 caliber can be loaded down to match a .45 caliber if you want. A .50 caliber is legal in most all states where a .45 for some game is not. A .50 caliber normally shoots a larger conical or sabot load which have more down range energy.
I am sure you will be real happy with the .45 caliber. Develop a good accurate load and place your shots and you should have no problem at all...