I just got this formula from David Kimble at
www.accuratepowder.com for reduced loads using AA XMP 5744 Powder, also very useful for figuring starting loads for cast bullets in any caliber rifle.
First determine where the base of your bullet will be seated in the cartridge.
Fill the cartridge to this point with XMP 5744.
Weigh the total powder in grains
Multiply by .4 with a calculator...this total will give you 40% case capacity and a safe reduced load in your firearm.
For example, my Whelen Improved holds 56.5 grs of 5744 to the base of the shoulder where I will be seating 210 gr cast bullets, multiplied by .4, gives me 22.6 grs of powder...
David is very interested in promoting beginners to learn to shoot without becoming re-coil shy. These kind of loads are excellent if you wanted to take your wife or teen-ager to learn to shoot. They could actually have FUN going to the range with us, instead of being 'punished' with full power loads and never going back again. Also, reduced loads can turn your Ultra-Mega-Macho-pain-inducing-Magnum into a realistic meat-getter for whitetails without destroying 40% of the meat.
