In my .54 caliber I shoot a 405 grain copper coated powerbelt. As for the 160 grains of Pyrodex RS that would be an over charged weapon. Perhaps you meant 150 grains and was a typo. Why you would want to push them that hard, must be a distance or game size issue I suspect.

The general consensus with powerbelts is, people run into trouble with them when they push them too hard. They powerbelt hits and then fragments. I can not confirm that from personal experience. Some people have some real good experience with powerbelts. Other do not have anything too good to say.

Does that rifle of yours have a 1:32 twist? If it does, a good conical like a Hornady Great Plains, REAL conical, Maxiball, might be a better choice. Also do not be so quick to push conicals all that hard. For deer even 70 grans is plenty if the range is 100 yards and under. If your hunting something else, that might be a reason to get the powder charge a little higher, or if your distance you want to shoot. Although if there is a distance issue, get some .54 caliber sabots and some 300 grain XTP's or some other good bullet, and see if your rifle likes them.