A shoota or slugga with the Blasta kustom job has extra heavy duty armour piercing ammo or is radically altered so that it fires a lethal energy bolt capable of burning through armour. A Blasta kustom job gives a shoota or slugga AP3 at up to 12" range, increasing to AP2 if the target is within 6". But a shoota or slugga with the Blasta kustom job gets hot just like a plasma weapon, so on a roll of 1 To Hit the weapon scores a wound on its firer; normal armour saves apply.
Errata — Chapter Approved: Codex: Orks Q&A (v1.0): The Blasta kustom job can be combined with the other kustom jobs (Shootier, More Dakka).