After shooting a beautiful buck like that with a bow you don't deserve a muzzleloader deer... Just kidding of course. That is a heck of a deer you got there.

As for your rifle, also check the stock and make sure there are no cracks in it. I have no idea what could be wrong with your rifle... perhaps the scope, but I doubt it. Although a Tradition's scope I am not sure who makes it. Is this a 1X power scope? Did you go back to 50 yards and shoot again, after it failed you at 100 yards? That might indicate a problem in bullet flight or powder amounts, but to open that much after stacking them at 50 yards.. well that just is not right.

And I am sure if you talked to Mike he told you all about swabbing between shots. And probably gave you lots of good tips on making the rifle behave.. so I am stumped.