Don't use the modifier. Duplicate it then hit Object (Or mesh if you're in edit mode) - mirror.
The slide-out stock looks like nothing on the real weapon.http://img.redwolfairsoft.com/upload/news/797/tm-oct07-mac10-2l.jpg
Pay up.
1. Then what's so special about your's? Reloading when you pull it out and when you fire a bit?
1 thing, make the trigger guard smaller and the trigger a little thicker and then, Wow.
:D I'm almost finished with the modeling