This is a model based in the 80's cartoon BRAVESTAR was an American space Western animated series. The original episodes aired from September 1987 to February 1988.

The gun was used by 30-30, a mechanical horse that transforms into a bidedal badass

This is a 3d model made in FUSION 360 and exported to some of the most common used 3d formats in the market, ready por printing since it was desined taking into consideratcion plastic thickness, pins and screws articulation and so much more.

I don't have a 3d printer so I can't test it but if you do, and wanna try and after you try it you find some things that needs to be fixed just let me know and I will fix anything gladly.