Different manufacturers & different burn rates. - Not exactly the same so use the specific manufacturers' data.[/QUOTE]
Yes. They are in fact two different powders entirely. Data for them is NOT interchangeable. The original Hodgdon 4831 was, apparently, war surplus 20mm Cannon propellant. One is faster than the other.
It is worth saying also that H4831 (the original "long grain") is also NOT the same powder as the newer H4831SC (the short grain). That is that H4831SC is not grains of H4831 cut in half or extruded into shorter lengths.
So they can be loaded H4831 and H4831SC to the same weight setting on scales but not to the same volume setting on a powder throwers or Lee's Popeye's pipes. They are different!