This is a short video of my m11 dumping a mag.
48 rounds.
It is a little over 2 years old and has over 30,000 rounds through it.
The only parts replaced in that time were the magazine feed lips for $8.
I have been running propane mostly as a propellant, sometimes green gas.
the externals are plastic, but the internals are all metal.
Price $105 with free shipping from most retailers.
great gun.
http://youtu.be/OsokRJScnIQ