It's the Russian's fault. When they ordered revolvers from Smith & Wesson back in the 1870's, they were interested in the .44 S&W American, but demanded that the cartridge be converted to use an inside lubricated bullet rather than the .44 caliber outside lubricated heeled bullet that was then standard.
So S&W kept the same diameter cartridge case but reduced the bullet diameter to .429 so that it would fit inside the case as an inside lubricated bullet. But they still called it a .44.
Thus was born the .44 Russian, grandfather of the .44 Special and .44 Magnums using .429/.430 bullets.
A stern letter to Vladimir Putin may be in order.
Yeah, maybe Vlad'll send you a picture of himself with his shirt off!
