The player (have not tested AI) may only have up to 13-15 bullet hole decals at any one time. So if you shot 10 rounds into a wall and 10 rounds into a car, 5 or so of the decals will have vanished from the wall...
Currently the decal is just a black mark so why not up that to 180 at least. That's the standard combat load for a us soldier.
http://thedonovan.com/archives/modernwarriorload/ModernWarriorsCombatLoadReport.pdf
Though, if you shoot the ground, it will contain way more (I did it at the air field). Don't imagine it's something that'll be permanent, but best to start prepared. +1!
Yeah, I tried it again and I only got 10 bullet decals before they started vanishing.... why should it matter what you're shooting at as to how many bullet holes it can contain?
Closing due to lack of activity for over 5 months. If this issue/request is still valid in the latest dev build, please create a new ticket or ask for this one to be re-opened.