I've seen guys' red dots fail during training and they were clueless how to proceed. Of course they hadn't ever zeroed their irons (what is co-witness?) so the rest of the training day was a waste for them.
I don't think I know the difference between accuracy and precision. Learn me something, what is it?
Accuracy is within a range, while precision is exact. Say, the 'A' zone on an USPSA target could constitute accuracy, putting a round in the center of A is precise - or better a group fist size versus a group at the same distance half-dollar size.
Ah, TIL. Thanks!