I'm not biased ronlaughlin. I just do my research and go by the thousands of reports. Even our resident CVA and powerbelt advertiser, MountainDevil54, has many posts about the need to load down the 338 platinum. I ran across one of his reports under his Frontier Muzzleloader ID that stated that exact thing. Stay off bone and load 90gr or less for close up shots because of over expansion and poor penetration. I'll try to pull the quote and put it up here. Not 100% sure how to do that but I'll give it a swing.
If you know the area you are hunting very well and have a good idea on the ranges you will be shooting, you'll be able to settle for less powder and get better penetration at shorter distances. Powerbelts are pure lead and like all pure lead conical bullets, pure lead plus high velocity plus close distance shots, often result in an over expanded bullet that has limited penetration, especially once it makes contact with heavy bone. Remember this and try to avoid hard heavy bone shots if the animal is a lot closer than you had planned on it being!
That was a direct quote from him while in the same article he was saying they were fantastic penetrating bullets. Just how can it be a fantastic performing bullet if it penetrates poorly, you have to stay off heavy bone, and you need to load it down for closer range shots? That doesn't add up to a fantastic performing bullet in my book. Or anyone else's with even a small amount of experience. That ads up to a sub par, not even close to a premium bullet. Now if you want to continue arguing about their poor performance, go right ahead. I'll take the word of the thousands that have had bad experiences with them as well as what I have seen for my damn self.