This weapon is actually a unique gamma gun mod installed in a regular gamma gun. The effect of the mod is that the gun fires unique projectiles that may significantly knock back enemies well above and beyond the normal stunning effect of a gamma gun, in addition to doing a different type of damage. One can remove the unique mod and install it into a different gamma gun, which includes legendary gamma guns as of patch 1.4.
Unlike the vast majority of radiation weapons, the radiation damage dealt by Lorenzo's Artifact is pure damage; it does not do radiation poisoning (in other words, it does not give rads to hit targets). Although it is still affected by radiation resistance, it isn't affected by radiation immunity, as radiation-immune targets have 0 resistance to pure radiation damage. 
While numerically a gamma gun has a higher "damage," the gamma gun and Lorenzo's Artifact have very different mechanics. The gamma gun has a core explosion component but is mostly intended to do its damage in the form of rads, which is effective based on the enemy's maximum health. Lorenzo's Artifact trades that off to do direct, unconditional damage. As a result, there will be cases where Lorenzo's Artifact's "lower" damage will actually be much more effective than the gamma gun, and there will be cases where the gamma gun will be more effective. See radiation weapon for a more detailed discussion.
When equipped with the electric signal carrier antennae, this weapon does a dramatically different set of damage spread across multiple damage types, generally boosting its overall usefulness against most enemies; it can furthermore be charged to do even more energy damage.
It is possible that the weapon was supposed to be non-lethal, as Jack Cabot states when giving it to the Sole Survivor, saying that it won't kill people, but the Sole Survivor might find it useful in other ways.
|Slot||Mod||Description||Weapon prefix||Range change||Perk needed||Components||Base ID|
|Dish||Standard dish||Standard.||–||–||–||–||–||–||–||–||–||Adhesive x1|
|Deep dish||Better range and damage.||Long||+||–||+84||–||–||+1.5||+72||Science! 4||Adhesive x2|
|Grip||Standard grip||Standard.||–||–||–||–||–||–||–||–||–||Adhesive x1|
|Sharpshooter's grip||Better recoil and hip-fire accuracy.||Sharpshooter's||–||–||–||+4||–||+0.2||+34||Gun Nut 2||Adhesive x2|
|Electric signal carrier antennae||Hold fire to charge additional electrical damage.||Electrified||Special, see below||–||–||–||–||+0.3||+30||Science! 3||Adhesive x5|
|Signal repeater||Improved rate of fire.||Automatic||–||+24||–||-2||–||+0.3||+60||Science! 4||Adhesive x4|
Footnote: The electric signal carrier antennae significantly changes how the gamma gun and the Lorenzo's Artifact version functions. The base damage changes to:
- Gamma gun: (direct hit) 54 + + +
- Lorenzo's Artifact: (direct hit) ; (area of effect) + 44 + 40
In addition, if one holds down the fire button long enough for the gun to start making a "clicking" noise from the arcing electricity, it will do an additional +45on a direct hit.
- Due to a possible bug related to Fallout 4 area of effect damage, the base, non-explosive radiation damage is applied twice on a direct hit.
- Because the weapon is actually a standard gamma gun with a unique mod, it is possible to replace the Lorenzo's Artifact mod with a standard dish and one can then install the Lorenzo's Artifact mod into another gamma gun. Doing so will rename the weapon to "Gamma gun;" conversely, installing the mod into another gamma gun will rename it to "Lorenzo's Artifact."
- Demolition Expert will increase the explosion damage, while Nuclear Physicist will affect the radiation damage.
- The player character is only able to get Lorenzo's Artifact by siding with Jack. Freeing Lorenzo does not result in Jack going to do extra research, therefore only the first method results in the pistol as a final reward, unless Lorenzo is killed without being able to kill any of the Cabot family.
- Lorenzo's Artifact seems to be highly effective at blowing off the armored shells of mirelurks, making them much easier to finish off with any other weapon, although the gun itself can easily be used to kill them as well.
- Lorenzo's artifact can sometimes hit the fusion cores on a sentry bot even without the Penetrator perk or the cores being exposed. This can often end the fight with one shot.
- Jack refers to Lorenzo's Artifact as a modified laser rifle using standard energy cells, which is not the case with the gun received, although the gun he is holding during the dialogue does appear to be a modified laser pistol.
- If put on a gamma gun with the Poisoner's effect and electrical signal carrier mod, it will be possibly the most versatile weapon in the game, dealing ballistic, explosive, energy, radiation and poison damage.
- If you wait too long before receiving the corresponding weapon mod as a reward, it is possible for Jack to age regardless of the quest and have his younger version disappear from the gameworld- making it impossible to obtain without console commands. Spawning young Jack in won't help either, as he will only mention that he has great news repeatedly and otherwise cannot be interacted with.
- The young version of Jack remains at the point where the quest marker points, albeit disabled. He can be enabled using the console command prid 47ec2, followed by enable, he can from here on be interacted with normally to receive the gun. (You can disable him afterwards. (He must be your target))
- Attempting to kill Jack can give you the Artifact Gun even if you've sided with Lorenzo.