They are; compare them to weapon 3. The barrels of 4 & 6 are way too short as well, 6 especially
being a rifle. They need more (radical) shading; the Steyr pistol looks the best.
Keep up at it! And your avatar is a red box for me...
8 & 9 look much better. 5's barrel looks kinda fat, and the RPG, being an RPG, is kind of short. 0 should have more color contrast (if it's dark, make it really dark, and vice versa). More shading on 2, and the wood of 6.