Interesting load, I'll have to give those XTPs a try in my 1:48 twist Seneca.

Got alot of those for my sawed-off Kentucky rifle, "Shorty".

I've had good luck with .45s on mulies in west Texas, but I was shooting 242 gn Maxie's out of a CVA Kentucky rifle.

The biggest of the three weighed 174 lbs, dressed. Longest shot was only abt 50 yds.

I don't really see that mulies die any harder than whitetail, in my limited experience with our (smaller?) Texas mule deer.

Sharp Shooter, I'd reckon that accuracy should decide for you... either of those rigs should put your deer on the pole, though I would lean towards a conical as better at bucking wind than a RB.

Good Luck!
BP