I finally found a post on gamefaqs that explains in depth on how followers' items work. Hopefully this will clear up the confusion regarding managing your followers' equipment. All credits to hitomi ownz me@gamefaqs.
I've tested this out and confirmed this with several other people, and here's how follower's items work:
- For their default gear, there is no ammo or durability, so they can continue to use those items forever.
- If you give them a better weapon than their default, they will use it only if it has ammo, and once it's used up, they will switch back to their default. Durability will be used up as well.
- If you give them any armor, they will only equip it if it is better than their default gear (for instance, Cross won't wear any regular Power Armor or Enclave Armor that you give her since she already has Power Armor, but she will wear a helmet since she has none). It will not lose durability, however.
- If you want to see if they are using the weapon, just ask to trade with them and you will see the square next to the item if they are using it.
Cross appears to have a normal laser pistol if you ask her to go ranged (rather than melee with her sledge), so you should check to see if she actually equipped the Smuggler's End one.
I tested this out by giving Cross fully repaired weapons such as a Xuanlong Assault Rifle, Flamer, and Minigun. If you don't have a fully repaired weapon, you can just check how much damage it does at the time you give the follower your weapon. Give them plenty of ammo and let them use it, and after a while check them again. You will see that the damage has gone down along with durability. I also did this with armor obviously, but the armor has never degraded no matter how much damage my follower took (this was also confirmed with several other posters on this board).
