I prefer H110 with the 454, it always gives great performance with any weight of bullet. I've used it with 240gr all the way up to 405gr bullets and it's worked great.
If your worried about the open space you can alway use a filler like cream of wheat or malt o meal.
I see the world thru bloodshot eyes
Streets filled with blood from distant lies
The dogs of war never compromise,
No time for rearranging.