Bought a Ruger 77 in 44 magnum. Sighted in with factory Hornady 240 grain XTP at 100 yards. Shot under 2 inch groups. Reloaded with Hornady 240 grain XTP bullets, new Hornady brass, Winchester large pistol primers. 5 each of 23 grains, 23.5 grains, and 24 grains of IMR 4227. Length of 1.6 inches. They shot about 6-8 inches low. Never loaded straight walled cases for a rifle before, so I am wondering if anyone has a suggestion as to why they shoot low. Could it be the crimp?