I load 15 rounds because of my OCD. The boxes of ammo I buy have rows of 5 rounds...15 rounds will empty three rows. If I load 16 rounds, it would leave an incomplete row...not empty, not full. 
I tried to do the math to figure out how many mags I'd have to load with 16 rounds to end up with all empty rows...but I ain't that smart, I guess, so I just load 15.

I tried to do the math to figure out how many mags I'd have to load with 16 rounds to end up with all empty rows...but I ain't that smart, I guess, so I just load 15.
