Logged back into UK Experimental server, all ammunition rounds in inventory (piles) read 0 rounds remaining, and had the 'Ruined' condition. This affected all types of ammunition, but none in any weapon were affected. For example, I had piles of 7.62x54R, .380 Auto, and .357 Magnum and all were affected.
The round piles could not be split but corresponding ammunition could be loaded into an empty weapon but would disappear without any action, and would not load the weapon.