[ILLusion]

Originally Posted by OM3GA

The best way to clamp the receiver is in a clamshell style upper receiver block. It prevents twisting and parts snappage like you see here.

Edit: Just like this one http://www.midwayusa.com/product/210...ck-clamp-ar-15

If this build is for an AEG, these real steel receiver blocks won't fit, as AEG receivers are wider. This solution only works well with GBBR's and PTW's.