Just purchased one, for my 12g 870 however. I ordered it in .660 constriction and plan on shooting some #7 nitros. Sorry no advice for your 835. Since I couldn't find any info on others patterning with the choke, I am kind of guessing and banking on the information they gave me being correct. But there is always guessing involved, I just hope it patterns well.
The chart on their website was created for their grand slam model choke I think. I would suggest calling rhino and ask for an opinion on the constriction. Make sure you tell them your intentions in regard to shot size. I would tend to think if you are only shooting 7s you could go a little tighter than they recommend.