I assume youíre talking about Buffalo Bore.
Yes, they are hot loads. The risk is using them in older firearms. I think thatís mainly the .45/70, since itís been around long enough to see some older rifles with steel that isnít up to the task. In more modern rifles made for higher pressures, itís fine. I donít know the specifics, but Iím sure the folks at Buffalo Bore can fill you in.
I love their ammo. I shoot it in my .454. None of your standard factory stuff can touch it. Only outfits similar to Buffalo Bore, like Cor-bon and Underwoods is in the same league.