Do I need to use this spacer to cowitness the irons on an M4 A2?
I plan to attach to this gooseneck:
Let me know if i got the right height, also let me know if that gooseneck rail will work with an M4
If you mount an Aimpoint on a flat-top upper a spacer is required.
If you mount it on a railed handguard a spacer is required.
If you mount it on top of an A2 handle NO spacer is required.
If you mount it on an Aimpoint or ARMS "gooseneck" mount, NO spacer is required.