I don't reload but when I'm doing somthing I want to be precise with I utilize 2 or more measurement devices.
One device with ability to calibrate/confirm is far more valuable than two devices.
“A man with one watch knows the time, a man with two is never sure.” But in reality, the man with two watches has reason to doubt both watches, and the man with one is blissfully ignorant to the inaccuracy of his single device. Rather, the true solution is the ability to confirm the watch, the device, against a known standard.
As an example of this fallacy in reloading practices: many reloaders will “check” their electronic powder dispenser by also massing (not weighing) the charges on a balance beam. In reality, when you get down to real analytics, most of these beams have no greater reliability, accuracy, nor precision than an electronic dispenser/scale. Temperature, lube or lack thereof, dust or lack thereof, a slightly different influence when the pan or charge is placed (velocity vs. stiction), humidity, even electromagnetic fields, etc can all influence a beam balance. In some cases, the beam has LESS precision and accuracy than an electronic scale. Let alone talking about linearity of the beam!!
So overall, in most cases, having two sets of calipers, or “confirming” dispensed charge weights on a beam scale is a false confidence.
One quality device with a means to calibrate against a known standard is the trick, having two devices with inherent inaccuracies is not.