juan pablo pozzi
AH senior member
I guided a client with a 4570 and it could regulate both barrels .So he used it as a mono shotI had one two years ago. Couldn't get it to regulate regardless of what ammunition or load I used. It was a 450/400. Both barrels shot great individual groups but nearly six inches horizontally and two inches vertically apart at twenty five yards. The muzzles hadn't been ground and yes I did have several people shoot it and none of them could do any better than I did. But full credit to the gun shop I bought it from , as they took the rifle back and gave me a full refund