You can weigh each completed round and compare to a known good cartrige.
I do this regularly, particularly if I'm loading ammunition with new brass of all the same kind, there are always tiny variations in weight due to minor inconsistancies in bullets and brass, but if it's the wrong bullet it will probably stick out like a sore thumb, a 5 grain difference would bury the beam scale at one end or the other.
NRA Lifetime Member Since 1999
"I ask, sir, what is the militia? It is the whole people except for a few public officials." George Mason