With regards to "weapon regulations" etc, what's done to ensure that your personal weapons is exactly that, personal to you ?.
by that I mean my personal weapon was an L1A1 SLR back in the day, obviously no rails etc, fixed iron sights & very rarely a fitment of a starlight scope for night ops, BUT something small that was done was the rear stock length was adjusted for optimum fit accordingly to size/arm length by way of spacer sets, now I don't know if this was done at company, battalion, or regiment level, or across all services, but I wondered if anything like this goes on now ?, obviously sights have to be zeroed but with picatinny rail systems most add on stuff can be altered in seconds according to your needs, by the user, but not necessarily in a way that improves marksmanship.