Mine shoots best with slightly reduced loads of 4350, in the 41-43 grain range using 100 gr gamekings. Even these are a little on the loud side (Klikitarik's 'bark') out of a 21" tube. I've been itching to try the 87's. It seems like those could produce good results with lower recoil, if that really is the problem. I would suggest using a little bit quicker powder for less report out of that short barrel. My 100 grain loads had a reduced report even with max listed loads of 3031 and 4064 vs 4350. I imagine that 4831 would be a little worse with your barrel length.
Happy Hunting!
