They really suck. I think I've said that before. :-)
Anyway, one of the reasons locks suck, is because of the short cuts they take to make them. What kind of short cuts?
Well, I measured several pins tonight. Key Pins (the pins in the key way), and driver pins (the pins in front of the springs), that actually cause it to need the key.
The driver pins were roughly 3 different sizes. My calipers do 3 decimal places, in inches mode. It has a 4rd spot for a 5. The 5 is either there or not, meaning about .0005 of an inch.
The driver pins I was working with tonight measured between 0.181 and 0.182 inches. The spooled driver pin from the same lock measured slightly larger.
I'll try again in MM and see what those numbers look like but not tonight.