Anyone know how similar the burn rates between these two are? I want to test both with the 129 ABLR in a 260 rem. The nosler page shows data for H4350 but I can't find much using IMR4451. The Hodgdon site shows 41.5 grains for a max charge using the 142 sierra MK. Probably safe starting at that load for a 129? Are the new IMR powders in quickload yet? Thanks for the help in advance.
