I have a ton of info regarding powerbelts in general. The 338gr Platinum is one I have always had a high recommendation on.
Pushing them ( powerbelts ) with 80- 90gr or sometimes less, is recommended for the lighter weight powerbelts. Back in the day with folks were heavily on this forum and coming here to ask about them, I did a ton of testing with the most popular 245 and 295gr powerbelts.
I've shot the 245 and 295gr powerbelts with 150gr of pyrodex rs and have experienced very little expansion on a couple deer. These shots however were well over 120 yards.
In all the years of hunting, We've recovered 3 powerbelts from animals and that is it.