Lyman's data, which was pressure tested using crushers, shows 4895 is quite safe with the 220 RN. In my 30" rolling block, their recommended starting load of 35.0 gr made 2000 fps, a little bit over what one might get in extrapolating from Lyman's 24" test barrel.

Even though I chose to try 4895, be warned that 4064 is a safer bet. The old Dupont data showed 4064 would be very safe for 2000 from 30" with 220 gr RN, but I've never been able to locate their 4895 data for that bullet. Their 150 and 180 gr loads show 4895 to have much higher pressure than 4064. Perhaps they had a poor lot, or perhaps 4895 has changed over the years; Lyman's data is the more recent.

Karl

edit: Sorry!, that H before the 4895 in your question hadn't sunk in, so my comments above are not relevant.