I have had 2 Valmet O/U's in 9.3x74R and one Chapuis SxS and have had excellant accuracy from all. Groups under 2" in all cases.With scope as I'm not that good with irons . My 100yd groups with irons run usually about 4"/5". I can sometimes keep my 50yd irons in 2". Used Valmet mounts on the Valmets and custom Ruger on the Chapuis. Since my Iron groups are not so good I can't tell you how the scope effects accuracy.