Wonderful!
It is what I was hoping and this is how you use it:
On the ammo item place the nameAsAmmo: followed by the string variable you want to use, example:
- type: STR_LAUNCHER_SMOKE
size: 0.1
costBuy: 300
costSell: 200
weight: 3
bigSprite: 63
floorSprite: 2
hitSound: 0
hitAnimation: 96
power: 60
damageType: 9
clipSize: 1
battleType: 2
armor: 20
attraction: 6
listOrder: 3413
nameAsAmmo: STR_NAME_OF_THE_STRING
In extraStrings: define the contents of STR_NAME_OF_THE_STRING and now when the weapon is loaded with that ammo this text is added to the end of the weapons name.
Very useful.