MAGNUM is the ultimate high performance magnum rifle powder. It provides outstanding performance from the popular 7mm Rem Mag and 300 Win Mag through the Remington Ultra Mags and 338 Lapua. It is a double-base spherical propellant that is the number one choice for high performance “overbore” magnum cartridges. Made in Belgium.
I reloaded 220 cartridges for my .300 RUM using Magnum and 180 Grain Barnes TTSX and achieved a .250 cold barrel group at 100 years. Being a spherical powder it work great for compress loads. I could use a source for this as I am running a tad low on my inventory.
What little loading I’ve done with the 257 WM, it seems it will be a good choice. (Waiting on cooler weather) this powder appears to have a lot of horsepower compared to others in this burn rate.
my 6.5 PRC loves it