Here is the heavy assault rifle which is an original design from Fallout Hobbies. While it's not based off of a gun in the Gundam universe (that I've seen), aesthetically, it does fit right in with the Gundam weaponry we've come to love! Included is an extra magazine and mag holder which can be mounted on the model kit of your choice.
This weapon is made from 3D printed resin. Kit is separated into 7 individual pieces and requires some assembly (Superglue recommended for final assembly).