1.AR2HVP, a semi-automatic lego brick gun, magazine fed with a similar system to a revolver, you pull the triger and a hammer is brought back, which then hits the bullet, no reloading of rubber bands needed, just stick in the mag and go. Its just got a few kinks to work out then I'll build it. Estimated range of 5m.
2.AR3RM, a mortar that fires either collections of little bricks, or 1 mars lander wheel, estimated range of 20m. Fully worked out, but I want to build the AR2HVP first.
3. AR4FAMG, fully automatic brick machine gun, similar system to the AR2HVP but powered by a wound up rubberband around a spinning beam (essentailly a really strong motor). This is realeased by a trigger, when the trigger is closed again, this can't move. When released this powers the hammer, when stopped the gun stops firing. Once I work out the AR2HVP, this will be in the works.
Current MOCs (may or may not be posted): AR1LRS, two shot semiautomatic sniper, accurate effective range of 15metres. Total range of 30metres. Accuracy at 15m within a 30cm diameter circle, accuracy at 5m within a 10cm diameter circle. Was going to have 8 shots, but lego couldn't hold the forces involved and all 8 shots went out in a fully auto spew of bricks, quite cool to watch, not so cool to get hit by.