By no means I would consider myself an expert but I think elevation between barrels has more to do with shooting technique than regulation. Heavy recoiling guns are very touchy to get to shoot and replicate factory regulation so I would consider those targets more than acceptable. I very well could be wrong on this, I am a long time rifle shooter but just got into doubles. For my bolt guns to shoot 1inch moe I really have to focus on my shooting and shoot consistently. Same pressure, hold etc. when I shoot my double if I apply the same principle and try to shoot barrels identically, I get good results. Quick target aqusition from different hold will put the shots higher or lower.