Krumpers are a weaponized industrial tool, a rivet cannon of sorts. Very short ranged,
they are effective in the close tunnels and conduits of the hive, but
much less impactful in more open Sector Mechanicus engagements.
Krumpers have two weapon profiles with a shared ammunition feed, and a fighter may select either weapon profile when making a Shoot action as as they prefer. One of the weapon profiles represents a charged up attack and has the Unwieldy trait to indicate the extra time required to get the attack off. Thus even though the other weapon profile lacks the Unwieldy trait and may be fired normally as a Basic action, the entire weapon is considered to be Unwieldy for purposes of how many weapons the fighter may carry.
Rapid Fire (X): When firing with a Rapid Fire weapon, a successful hit
roll scores a number of hits equal to the number of bullet
holes on the Firepower dice. In addition the controlling
player can roll more than one Firepower dice, up to the
number shown in brackets (for example, when firing a
Rapid Fire (2) weapon, up to two firepower dice can be
rolled). Make an Ammo check for each Ammo symbol
that is rolled. If any of them fail, the gun runs Out of
Ammo. If two or more of them fail, the gun has jammed
and cannot be used for the rest of the battle.
If a Rapid Fire weapon scores more than one hit, the hits
can be split between multiple targets. The first must be
allocated to the initial target, but the remainder can be
allocated to other fighters within 3" of the first who are
also within range and line of sight. These must not be any
harder to hit than the original target...for example if a target in the
open is hit, an obscured target cannot have hits allocated
to it. Allocate all of the hits before making any wound
rolls.
Rapid Fire also works in close combat when on a weapon that also has the Pistol trait.
Blaze: After an attack with the Blaze trait has been resolved roll
a D6 if the target was hit but not taken Out of Action. On a
4, 5 or 6 the target catches fire; place a Blaze marker on their
fighter card. At the end of each of their own activations a fighter
who remains on fire suffers a Strength 3, AP -1 and if they are not prone the fighter
becomes Broken and begins Running for Cover.
An Active fighter with a Blaze marker on their fighter card may make the Stop Drop and Roll (Double) action;
if they do the fighter becomes Pinned (if they are not already prone);
roll a D6 and add 1 to the result for each friendly Active fighter within 1''.
On a 3+ the fire is extinguised; remove the Blaze token.
On a 1 or 2 the fighter remains on fire and their activation ends.
Friendly fighters within 1'' of a fighter with a Blaze marker on their fighter card
may make the Extinguish Blaze (Basic) action; if they do roll a D6.
On a 1 is rolled the friendly fighter catches fire as well; place a Blaze token on their
fighter card and their activation ends.
On a 4+ the fire is extinguised; remove the Blaze token from the on fire fighter.
Exiguous: Some weapons that have multiple profiles share a single source of ammo, a common reservoir of fuel, or a shared breech that must be cleared in case of a jam. If any one of the weapon's profiles with this trait is Out of Ammo, all of the weapon's profiles that have this trait are also Out of Ammo. A successful reload of any one of this weapon's profiles that have this trait reloads all of this weapon's profiles that have this trait.
Unwieldy: A fighter who uses an Unwieldy weapon to shoot in ranged combat
treats the Shoot action as a Double action. A fighter
who uses an Unwieldy melee weapon in close combat cannot use a second weapon at the same time.
Unwieldy weapons take up two weapon slots.