I think the idea of sub-categories was good, but I also agree that there are far too many. I think a couple of them could be condensed to make viewing easier.

For example:
AK RIFLES
AK PARTS, ACCESSORIES & MAGAZINES
ALL OTHER LONGGUNS
ALL OTHER LONGGUN PARTS, ACCESSORIES & MAGAZINES

I think making that all ONE sub category would make the page easier to view. There are a few others that could be combined as well.