I've only recently noticed this during periodic maintenance. In our house here in AZ, we keep all of our weapons hot. I'll just have to remember to put a different round in every time, or just put the round in the chamber myself and then ride the bolt forward and manually assist it.

It would seem moot that cycling the same round in all the time should matter, how many SM's cycle the same round back in while in deployment? I know I did when we carried hot while deployed in Bosnia.