A while ago I suggested some variant of the Laser Musket from Fallout 4, but mechanically we couldn't seem to get past the recharge bit. I thought about it some more(IE I totally forgot about it until sometime today), and I have an idea regarding it that might work:
The laser musket would be an upgradable homebrew early laser tech, probably would do around 20-30 damage and have a high number of shots before the generator blows, it's also a heavy and sturdy weapon, so a gunbutt attack is reasonable.
Problems for the early version would be near musket level accuracy and a very high aimed shot ap cost, with either no snap, the exact same ap cost as aimed, or a high cost snap, to mimic the manual recharge. It would have to be a two hand weapon, can't shoot it if you've got your hands full.
Upgrades I can think of could include lowering the ap cost(better generator), sharply increasing accuracy(better laser focusing), removing the ammo count completely(better generator part 2) and increasing damage(meh, got nothing), also the standard upgrade of melee attack.
Another idea related to this if, if we could have a weapon that requires an action to 'cock' it, the laser musket could have a very cheap aimed attack, for aimed at least) and a good snap, but require an expensive recharge action before it can be fired again, with upgrades lowering recharge time and number of shots before recharge is required. I think this was the point where this idea fell flat, but I can't remember if the coders ever said if it was possible. It could be useful for other weapons, cheaper attacks with a cock action before you can start them, semi auto would just need to cock once per clip, and auto weapons wouldn't need it at all.