Companion ammo (Fallout 4)

Magical companion ammo is for use in companions' weapons in Fallout 4.

Characteristics
The "magical companion ammo" is the ammo that the companion's default weapon uses, and always is used when not having any weapon equipped. This type of "invisible" (and infinite) ammo is called "magical companion ammo".

Active follower companions equipped with any melee weapon (their own or provided by the player) don't consume any ammo at all. A companion can pickup a weapon and ammo on their own from defeated enemies and use it when fighting.

The only way for a companion to spend "real" ammo is when all three of the following conditions are met:
 * 1) The companion has a weapon equipped in their inventory (a weapon that can be seen equipped in their inventory when trading with them).
 * 2) The companion has at least 1 (one) ammo that can be seen when trading with them used by the type of weapon equipped.
 * 3) The companion is the current active follower companion.

If all three conditions are not met, or at least one of those cease to be true, the companion will stop consuming "real" ammo, and as the active follower, will switch to his own default companion weapon that uses "magical companion ammo". But if is not currently the active follower companion, then he will carry on with the same game mechanics for weapon and ammo that apply to the settlers.

Settlers can be equipped with a gun by the player and they will not consume any ammo, but in order to use that weapon, they need to have at least 1 (one) ammo in their inventory of the type that the equipped weapon uses. That single ammo will never be consumed and act as infinite ammo.

So, if a weapon is given and equipped in the companion's inventory to use and actively following the player character, they will need to be supplied with ammunition for that type of weapon. If no ammo is supplied (or runs out when using it), the active follower companion will then switch weapon for another preferred weapon that he has ammo for. If no other better preferred weapon is present, then he will switch to the default one (which magically never runs out of ammo despite not showing as having any at the companion trade screen).

If the companion is dismissed at a settlement, by activating another companion as follower, or just by dismissing him to a settlement by chat options, he will turn to use the settler's/provisioner's weapon and ammo mechanics until he is set as the active follower companion again.

Active follower companions will use their own weapon (the ones in the list below) and will never run out of ammo (since they "use" the "magical companion ammo" that, as their own gun, does not show up on their inventory when on the trade screen).

Locations

 * In companion's weapons. Replenishes automatically.