"I wonder about" 2.0, How do you look at a gun and determine round count?

[Gunanddoglover]

Operators got to know the round count.

 

[emptyMAGS]

 

[GodBlessTheUSA]

And on the opposite side of the spectrum:

HK guys (MP5, 93s, etc) want "Real, Genuine" HK parts, like the bolt, etc. So I can get an HK Bolt from 1969 and pay a mint for it because, ya know, it's genuine HK. Round count? Thousands and thousands....

BUT... the Bolt and BCG in my AR are decrepit after a few hundred rounds....