new powder

[bubblegump]

I recently bought some vihtavouri 560 powder for my 7mm rem mag and 300 win mag and out of three different loading manuals they give the maximum loads on the 180 grain 308's varying as much as 10 grains- from 67 to 77 grains max-has anyone here had any experience with this powder and the bullet combo? they are 180 grain partitions and I am wondering where to start

 

[DrMike]

Charge weights vary depending upon multiple criteria. Lot-to-lot variation in propellant accounts for significant charge variations in many instances. Differences in firing systems, the brass that is used, etc. all contribute to differences. The fact that you are using a relatively slow propellant tends to exaggerate any small differences. I would recommend that you select a load, working up in reasonable increments, measuring velocities and watching for pressure signs.

The VhitaVuori powders are among my favourites. I've used many kilograms of VN560 in a variety of cartridges. It will work well in the cartridges you mention.