I guess I just don't understand the big deal? Most guns aren't going to reliably run that lightly loaded ammo, even suppressed, without going down in recoil spring weight. Go down to 13lb or so spring and it would probably run 100% with anything you put in it. Is it that people expect it to run 100% out the box? CZ isn't going to put a different recoils ring in the SR model since they know 90% of people who buy it are not going to run a suppressor on it anyway.