BrickArms are taking LEGO compatible weapon making to the next level by overmolding the stock and handle in different colours. This StG44 looks amazing, however the process of making these is very time consuming to produce, with a defect rate higher than normal.
The mould is designed so that two colours can be injected one after the other. The plastic shrinks, so the entire gun would not fit into the second cavity. So you only include enough detail to “register” the gun to inject the grip and butt stock around. Since nothing is overmolded on the front of the gun, there is no need to cut a detailed cavity for it to sit into. This process saves lots of machine time.