M4 Carbine/M16

Here is a gun I’m working on, its based on a M4 Carbine/ M16. I tried to be as accurate as i could but inexperience and School-blocked computers caused that to be difficult. its not textured. Wondering anyone has any advice to make it better.

did you use reference images? it seems ok but some parts seem a little off

i had to use different pictures for different parts of it because most were blocked, what parts do you see that are wrong?