I have that same Burris scope on my Taurus Raging Bull in .454 Cassul. Well, if you can get it up to 6x without problems, then you are doing better than me because the max that I can get it to (and still keep a clear picture) is about 4x or so. I'm not THAT tall (about 6'0"), and I don't have gorilla arms, so I don't know why my max seems to be about 4x.
I must say, however, that the scope has help up perfectly, even with heavy 300 grain loads.
Zachary