Real Steel Buffer and Buffer Spring in Magna
 

Real steel buffer and buffer spring installed in Magna system (more specifically an AGM). Fairly old video, thought it was neat that the rifle actually cycles. The ATF considers the lower halfbreed of gbbr's to be a firearm. Anyways I don't recommend putting real steel parts in your gbbr cause I guarantee the guy's AGM in this video busted not too long after this video was created. All of this is old news but it's cool to watch anyways.

YouTube - Real Buffer and Buffer Spring in AGM GBB