My answer would be it depends. That is with no experience making hefes. I have bottled almost every beer I have made in the last 16 months in Stone bombers. I have calculated levels from 2.0 up to 3.2, with no failures yet. My saison at 3.2(projected) is highly carbed, and have not had any issues with bottle bombs. Someone more experienced with bombs may have a different answer, but 4 vols seems like it could be a problem. When doing my saison, I asked about the same question and think, with the bottles I was using, the consensus was to stay under 3.5 to be safe. If you have LHBS bought homebrew 22's, I dont know if they will be any stronger or weaker. I am interested to hear what others have to say on this subject though