CZ 455/457 Barrel Shims Barrel shims are used to adjust the barrel forward, away from the bolt face. This results in a longer headspace. Some replacement barrels are intentionally made with a too-long shank so that you can adjust headspace with barrel...

CZ-457 Head Space Bolt Shim Kit Custom tune the head space on your CZ-457. Factory rifles and aftermarket barrels are made to head space within a very narrow dimension called "SAAMI Spec". And that's all they normally need to shoot accurately and...