bradb

I have looked a lot and am pretty confused on shimming my SBE and how it efffects POI. I have an old H&K that shoot low/left and is magnified with a turkey choke. It has the original low rib, not the stepped rib of todays guns. I currently have the D shim and D plate that was in it when I bought it used. I have a set of shims on the way from benelli. Short of just experimenting, can someone help be out?