reduce poly count

is there an easy way to reduce poly count on my gun?

decimator.

Go into object mode, then turn down the decimate slider and click decimate

Or course, the easy way is not neccesarily the best way…Decimator makes (for lack of a better word) ugly stuff, mainly because it tries to save every single little detail. Depending on the model, it may be better to do it by hand or (if you have no patience or time) just make a new one.