Its unfortunate that the companions can't use the ammo for their default weapons with a better weapon that accepts the same type of ammunition. Such as giving Veronica the 10mm SMG rather than her 10mm Pistol.
i never even knew veronica had a 10mm... i gave her pushy and a ballistic fist and i've never seen her use anything else. i have been using her all game and she is a great companion. armed to the teeth, no ammo problems, and power armor...
but this play-through I am siding with caesar and I know he will ask me to blow the BOS bunker... in which case veronica will no longer be an option... so i'm trying to find a suitable replacement and arcade gannon was my first choice... i guess i could try lily since this ammo thing seems like a non-starter...