I had a few ideas on parts to make things more interesting.
Elemental barrels: Add a small portion of other damage to a weapon.
Plasma fussing inducing barrel chamber: turns you bullets to plasma.
other unique barrels
time: slows down the bullets so they can penetrate velocity shields.
dimensional: to penetrate phasing shields.
Splatter: changes the dynamic nature of the bullets making them act as a liquid temporally and causing the to splatter all over.
Spread X barrels: shoots a number of bullets in a horizontal patter that is determined by the number of barrels X.
space bending: lets oyu make imossible shots but also is need to penetrate certain armors
bullet types
Homing: seeks target and that target only.
Hornet: bullets linger in the air for a short time, attacking targets that enter their proximity.
Ricochet: they bounce around the room,
Hand grenade:
teleportation: teleports its self to you enemy's location.
Inferred Homing: the grenade has a good chance of seeking out a living target
Intelligent Homing: it seeks your chosen target.
Bouncing: it can bounce a number of times before exploding.
Gravity: sucks enemy closer to its position, before exploding.
Floating: it hangs in the air, ignore objects in its path. glides in a strait line, not lobbing like normal ones.
Flying: can head around corners.
Flying zigzag: goes all over in a attempt to stick a target at comple random.
boomerang: it explodes then comes back to your postion to expode again.
Ricochet shrapnel: the shrapnel has a chance of doing extra damige.
flaming Barricade: creates a short flaming barricade, a fire wall
Biting: like a sticky grenade, also causes bleeding.
sticky: throwing it at an enemy will cuase it to stick, so that enemy is a watking time bomb. a creature such as a dog wont be able to remove it.
lava: a fire liquid fountains out each turn phase and progressively fills the area.
glacier: creates a ice barrier that will explode after designated turns.
tundra: turns the ground to ice