Noob from WV

[Variable]

bgb,

Same bolt, Beo upper will work fine for Grendel, but not the reverse, because the Grendel port is smaller and narrower than the Beo port.

BUT....Uppers are cheap, (less than $100), so why kill your Beo to build a Grendel? Everything else is usuable in both, so I would just pick up another upper to build the Grendel.

THIS X 1000! Don't kill an upper for such a small price difference!