Unless you're a big fan of heavy recoil, you probably won't want to be shooting max power loads. For that price, you can't really go wrong.
If you are really concerned about the integrity of the slug barrel then put a micrometer to it. Mic the thickness from the inside of the chamber to the bottom of one of the holes and then mic the thickness of the chamber where there is no hole. I don't know the specs, but if you post those 2 readings on here, I am quite sure someone will be able to tell you if minimum tolerances have been compromised.
cookiemann