It's because that "resin kit" is just a recast of an old SD Studios kit someone assembled together wrong. Thank that person lol The barrel IS supposed to be to the side on it, too. Just depends on which recast version you got.That's why (for the price I got mine) I thought wasn't too bad initially thinking these would be between 25-35 dollars). When I re-visit target I'll check again. Have never seen even the Batarang in store so I'm not hoping for much.
Edit: Took some photos of mine (don't have batteries yet and cant figure out how to get the battery cover open)
This is bigger than the old resin model kit. The chamber does move and with some modding it looks like you'd be able to separate this into two pieces. Also!! The biggest thing I wondered, the nozzel is slightly to the side compared to the resin kit. A big win for me and I will defintly buy a few more if I see them in store. 100% pleased!