I had an Bruno ZH combo 7x57R/16ga. adaptation - 16ga. barrel was blown and replaced with 7,62x54R - it ended as a double 7x57R over/7,62x54R under - with ZH you can shoot both barrels with second trigger (first under then over) - front trigger was sawn off and it worked allright. have used it on a couple of roe and red deer as well as on boars - would definitively pick 7,62x54R over .308 win.