Correction -previously stated "I am using VV N133 and have found the burn rate only a bit slower than 3031" . Not so!

I have found that different powder burn rate tables do not always agree !
Some have shown 3031 and N133 next to each other - meaning no real difference in burn rate. Others have shown one a bit faster. So, I am assuming that there is no significant difference in burn rate between N133 and 3031 . This greatly simplifies comparing load data when having well documented load tables for one powder and not the other. For example, the interesting 45=90 Express loads on Loaddata.com all use 3031 powder.

Fortunately, I have found that the Lyman 50th Edition Reloading Handbook load data for the 450 Marlin includes detailed data with both 3031 and N133.
For the lighter bullets of 300 and 325 grains, there is no significant difference in velocity per grain of powder, but for the heavier bullets such as 350 and 400 grains, N133 takes the lead in velocity per grain of powder. N133 performs better WRT measured pressure too, averaging 1000 psi less at the same velocity.
THIS is what I have been searching for! Now off the computer and on to the loading table.


Last edited by crshelton; 11/12/21.
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