It really kind of gets me, the way these muzzle loading companies used market advertising to sell more rifles. Then the scope manufacturers had to jump on the band wagon as well with this magnum craze. Every one needs this new rifle because it shoots 150 grains of powder, and then this scope because it is all set up to shoot dead on at the aim points for you.. Horse Hockey!! We were shooting deer grave yard dead with 70 grains of Goex and a roundball for years, before a inline rifle made the scene. Granted we were not shooting 200 yards with them, but then we never intended to. We got close and made the shot count.
The majority of muzzleloaders while they can handle three 50 grain pellets, do not achieve their greatest accuracy with those kind of charges. Further the uninformed consumer was lead to believe that they needed to shoot magnum powder charges in order to kill anything. It was even suggested that those hunting deer with anything less, heaven forbid a roundball, were under powered, and just not with the game.
What the man at the range was getting at is, you'll most likely get much better accuracy, save money, not beat yourself up with recoil, and still get the job done by shooting 100 grains or two instead of three of the 50 grain pellets. 100 grain charges is a lot of powder and power. Look at the buffalo hunters long ago, they shot much lighter loads then many of us are currently shooting in our rifles. Even so, they killed millions of buffalo.
What I suggest you do is use the pellets to get used to the rifle and get the scope shooting reasonably good. Use two 50 grain pellets. A 250 grain Shockwaves would be a good bullet to shoot, but there are better hunting bullets out there. Remember, T/C has a stake in them Shockwaves so they want you to purchase them. Plus they do shoot well. And are a good hunting load.
When you run out of pellets, get some loose powder. I am sure some of the Triumph and Omega owners can give you some real good hints on the powder to shoot, the amount to shoot and the bullets that will best serve the kind of hunting you do. You got a great rifle and scope and it will serve you a life time. Learn what it likes. Good luck with it.