1st. Surplus powders will not be listed on comercial burn rate charts.
2nd. RVO didn't make the powder. They purchased it from a govt. surplus auction.
3rd. RVO should have run tests to verify that its burn rate is approximately close to what they're selling it as.
4th. 4350 what? There are 3 different powder manufactures that make a powder designated 4350 in their line up, each with different burn rates, and different charge weights for the same projectile. (Hodgdon H4350,IMR IMR4350, Accurate XMR4350). Which one?
So, You need to check with RVO and find out which 4350 they are comparing rv0-62 to. Then consult published load data from that company. If RVO has done there homework they should give you something like " powder burn rate comparable to XXX4350, starting loads should be reduced by #% and work up slowly from XXX load data".