Judging from the screenshots, the texture looks good! I have some constructive criticism to offer:
- The barrels have too much geometry going around the circumference of the model (I'm guessing 32 vertices all the way around) when it could be as low as 12 or 8.
- The extruded rings around the body should be part of the texture itself.
The triangle count can depend on the game and personal preference, there's no correct way of making a retro-style 3D model. I think these models would be too many triangles, especially when placed with multiple barrels. I think it's a good start but could use some triangle reduction.