It states that you 'ignore the ammo rules whilst on ready status'. Which would mean no-one goes out of ammo during shoot reactions. It doesn't make your weapons into infinite weapons, so pack weapons still cannot react fire etc.
It doesn't mean that you get free reloads for your one-shot! weapons or anything like that.
For that you need to buy an ammo dump and ready whilst in contact with it, or have autoloaders.