This mod adds a few legendary weapon effects from Fallout 76. Not all of them, since there are a few that I think are pretty worthless, but I added a couple I thought were cool and/or interesting. Here's a list of what you can expect from this plug-in:

• Quad: Quadruples ammo capacity. I know Never-Ending exists, but I can count on one hand how many times I've gotten that as a drop, and besides, isn't reloading a gun half of the fun? This effect is applied before attachments, and won't spawn on weapons that disallow Never-Ending; gatling lasers, laser muskets, syringers, junk jets.
• Executioner's: 50% bonus damage to enemies below 40% health. I didn't rebalance this one.
• Medic's: Completely replenishes HP on a critical hit. In 76, it would heal 5 HP over 1 second to you and nearby teammates, but it's honestly quite worthless. I may have overcompensated though, so I might reduce the amount of HP you get.
• Aristocrat's: 5% extra damage per 1k caps your character is holding, up to a limit of 50k caps and 50% bonus damage. Same damage limit as in 76, but a higher amount of caps needed in order to achieve it.
• Vampire's: Restores 5HP for 2 seconds. This is a slight buff compared to its version in 76, because Fallout 4 is far more generous with the amount of health you can get.
• Weightless: Weapons weigh 10% of what they normally would, before attachments.
• Fusion Powered: Adds 15 points of energy damage and can turn enemies to ash. This isn't actually a thing in 76, but it feels like a decent way to pretend I have a crusader pistol.
• Bloodied: Will now spawn on ranged weapons.
• Furious: Will now spawn on ranged weapons.
  

There are various effects I didn't bother with for various reasons, and I decided to just completely omit armour because, well, weapon effects are more fun. There is one slight issue in this .esp where if you pick up an Executioner's weapon, your character will grunt as though they've just taken damage. I have no idea why this happens, but you don't seem to be taking any actual damage, so don't be alarmed.

Another thing I noticed while testing this is while spawning legendary mobs with the console, they would, for some reason, drop un-legendary gear at their feet, and if you picked it up, it would be removed from your inventory and then transferred to the NPC's. If you left it alone, it would automatically disappear and then go into the NPC's inventory. Was this always a thing? I've never noticed before. Either way, I don't think it should be too big a problem. If you're playing naturally, the item should have already transferred to their inventory before you catch sight of the enemy, so it should be fine. I hope.

To install, drop the contents of the .zip file into your data folder. Don't forget the scripts, otherwise the effects won't show up without console commands!