If the front bead is lower because of the swamped rib, it may be causing you to have an issue with where you are seeing the target in relation to the muzzles and where you are shooting as a result, same as if you have too much drop in the stock, causing you to shoot low.
Before everyone gets their panties in a wad about looking at the bead, please understand that is not what I'm getting at, only that you are not seeing enough of the barrels or the bead AS A REFERENCE IN YOUR SUB-VISION in order to make the pattern hit where it should. Go pattern your gun.
JR
