You also didn't say how far your shot were likely to be. If they were not much over 100 yards, a bigger conical (such as the 460 grain No Excuses bullet) would also be a good choice.

If you compared the nosler to the NE, then you have a real delima.

And as far as comparing energy, I firmly believe that foot lbs don't give muzzleloading bullets their fair share. Here is another way to look at "knockdown": http://www.loadammo.com/Topics/July02.htm

All this is great paper exercising and fun, but you current load with the NP is a great load. At this point I wouldn't mess with a known successful formula.

Good luck!