I recently got Substance Painter free with my work, so I made this model to try to get to grips with it a bit better.
It’s heavily based on this amazing model by Rob Shaw (just not quite as good lol) as I was focusing on modelling and texturing skills rather than physical accuracy.
Apart from the gun, the bullets and the map, all other assets are from Polyhaven. I also used the excellent dust shader from this video to add extra realism in the first scene.
It was also a really good exercise in lighting, trying both naturalistic and studio styles. I still feel like I’m stumbling around until something works, but in this case I think it came together pretty well.
Base model vs Subdiv 2:
Behind the scenes:
You should be able to download the model from the Sketchfab link above 
ArtStation: https://www.artstation.com/artwork/Dvalk9