Artillery shells from a main bus type setup. Inputs are propane, coal, iron, water, green circuits, plastic, and steel. Constant combinators are to indicate what inputs go where. Probably slightly overbuilt, but I didn't have one so figured I'd make one. BTW, the artillery turret visibile in the image isn't part of the blueprint. =) Also, have bottleneck running in the screenshot, but the blueprint itself doesn't contain any mod parts.