Makes sense that it would do the same damage as the hunting rifle. Anyone know of a mod that boost its damage?

Why would it make sense? Part of the velocity of a bullet is generated by the barrel itself. It puts some spin on the bullet which helps reduce air friction as it travels to it's target. Since the Hunting Rifle has a much larger barrel, a .32 bullet is going to end up with a higher velocity, which translates into greater damage.

You could just modify the existing Chinese one, it has a longer barrel. Just give it the performance stats you want, give it a new formid and spawn it with the console.