Yup! My trips through batches of of the 4831/4831SC just amplifies what we all have heard or LEARNED through the years: Every batch is a law unto itself and powder charges usually requires some tweaking before a previous result(s) can be duplicated.Yes, and no....kinda. Per Hodgdon, they are identical in reloading data with the only difference being the length of the granule. So yes, they are identical.....in theory.
It's not uncommon for a person to open a new can of SC and find that the same thrown charge does not weigh the same as the previous can of powder. There seems to be a wider variance from batch number to batch number with the H4831SC which is sourced by Hodgdon from a powder maker from Scotland named Nobel Enterprises. Because of this, I would load for testing only when opening a new can from a different batch. While not always easy to do, the local gunshop I buy from buys in fairly large lots, their powders. I check to see how many of the same batch/run number they have in stock and buy a can with the largest same run number of cans for sale. Then I run a test load thru the gun and if it comes out the same, go back and buy several cans of the same batch number. I run into fewer problems doing it like that. Sometimes it works out, sometimes he just doesn't have enough of the same run number to matter. Sometimes there are differences, sometimes not. I've become more accustom to buying powder by the 4lb can these days just to eliminate the variance from batch to batch. YMMV.
FWIW, another one to watch carefully is H335. By chronograph, there can be a 12% difference in velocity from batch to batch. I'd call that significant.