This question came up at the match yesterday, where we shot 06-03 "Can you count?" as a classifier.
String 1: Engage T1 with five rounds only. Perform a mandatory reload and engage T2 with five rounds only.
String 2: Engage T3 with five rounds only. Perform a mandatory reload and engage T4 with five rounds only.
There was a discussion as to if it is legal to download your mags to only 5 rounds so you don't go over the Virginia count, or must you load to the division capacity?
Perfectly legal but why would you want to go to slide lock? Better to run 6 and 4 instead. What happens when you have a jam and you rack out a live round?