IMR3031 wasn't used or developed for the U.S. military. That was IMR4895. No such thing as 30 caliber 1931 either. There was .30 M1 with its 174.5 grain BT bullet at 2640 fps and .30 M2 with its 152 grain bullet at 2700 fps(later upped to 2800 fps to match the ballistics of the 168 grain .30 AP ammo). The last was the ammo used in W.W II.
IMR4064 gives more consistent accuracy with 150 and 168 grain bullets than either 4895 powder. Varget will do as well. So will several other powders that give around 2700 to 2800 fps. with a 150 or 168. Regular LR primers. CCI "milspec" primers are nothing but magnum primers. And the rifle nor the primer do not cause slam fires. Those are caused by improperly loaded ammo. High primers usually.
The M1 Rifle will use 150 to 180 grain bullets with no fuss(neither did the box or two of 220 Silvertips I shot, long ago. Blew a ground hog into next year with one.). 150's are easier on the shooter and the rifle though. However, if you're shooting matches, use 168 grain match bullets out to 600 yards and 175's past there.