Bullet printing attachment mineral energy gun.

[Longestarmlonglaw]

An energy weapon attachment (Or a new gun altogether) As an internal bullet fabricator built into it which runs off the materials you insert into it and recharger power, You still have to recharge it like a regular energy gun, as it runs on both materials to make bullets and recharger power to print them, no magazines unlike regular ballistics.
Think of it like a golem consuming minerals, but its a gun consuming it for special bullets.

Special effects of bullets:
Iron: Nothing
Glass: Increased embed chance, more bleeding
Silver and gold: Hollowpoint, worse AP, but better damage overall
Uranium: Very high AP
Diamond: Just extra damage
Plasma: Sets the target on fire
Bluespace crystal: Teleports whoever is hit.

The upfront printing of the gun (kit) is not very high, its main cost comes overtime from feeding it materials to use it.

[ju45he]

You would have to find some way to nerf blue space crystals by maybe making it inject them with blue space dust instead of an instant teleportation. Imagine a HoS getting ganked by 7 revs just for 4 of them to be teleported away, 1 burnt to a crisp, 1 with armour being invalidated, and the very last one bleeding to death in maints form a glass bullet.