It's not terribly uncommon to find pistols that are capable of head shot accuracy out to 50 yards and beyond. However, the accuracy of a pistol, is very rarely the long pole in the tent, so to speak. That's true even at the range, when conditions are ideal.
I can consistently hit my 5 inch steel plate at 50 yards with my 22/45, probably due to the countless bricks I have put through the gun. Although with my SR9C I only hit it maybe 1/3 of the time. If only my 22/45 was a viable choice for a SD gun.