Forster Rimmed & Belted Headspace Gage .257 Roberts NOGO

The Forster Rimmed & Belted Headspace Gage .257 Roberts NOGO is a precision measurement instrument designed to verify dangerous headspace conditions in rifle chambers. Headspace—the distance from the breech face to the base of the cartridge when the action is closed—directly impacts both accuracy and safety. Excessive headspace allows unsupported brass to rupture under firing pressure, venting hot gases backward with violent force. This NOGO gage establishes the upper limit of acceptable headspace; if the bolt closes on a NOGO gage, the chamber is out of spec and requires correction before firing.

Forster Products manufactures these gages to exacting standards with painstaking precision. The .257 Roberts NOGO gage is calibrated specifically for the .257 Roberts cartridge—a rimmed, belted centerfire round developed for medium game hunting and long-range rifle competition. The NOGO designation means this gage represents the maximum permissible headspace dimension; chambers that allow bolt closure on a NOGO gage indicate excessive clearance. Reloaders, gunsmiths, and precision rifle builders use paired GO and NOGO headspace gages to verify chamber dimensions during rifle builds, repairs, and quality assurance checks before test firing.

This tool is essential for anyone responsible for rifle chamber integrity—custom gunbuilders, armorer-level maintenance personnel, and reloaders who demand accountability over firearms safety. The compact 3.75 x 0.75 x 3.75 inch dimensions allow easy storage in a shop or range kit. Because headspace errors can result in catastrophic firearm failure and injury, using calibrated Forster gages rather than relying on visual inspection or assumption provides objective, repeatable verification that chambers meet published specifications before live fire.