SP-D 828 7.62mm Semi-Automatic Sniper Rifle

Hey Guys, I am working on a new personal piece for my upcoming project. This is the main weapon for one of the characters. I also designed this to practice hard surface and weapon design. There are a lot of mistakes & areas I can improve, but for a character artist like me who is not a professional weapon designer, I need to start from somewhere.
There is no 3D involved so it's all photo-bashed and painted. Maybe I shall learn to be advanced at blender someday, but I'm just addicted to painting at this moment.
The name SP-D 828 means Sniper Rifle designed by Ding on 08/28.
Special thanks to Daniel Solovev's old tutorial, it helped me a lot during the process.