Forster Products manufactures precision headspace gauges to maximize safety and accuracy in your rifle. These gauges are necessary when finish chambering a barrel, or when checking the chamber of a used gun to be sure the headspace dimensions are within safe limits. Machined from A2 tool steel, these gauges are held to tolerances within 0.00015″ to ensure accurate testing of your rifle’s chamber.
The BG300MN is a No-Go gauge designed for 300 Magnum and all belted magnum cartridges with a .535″ O.D., including popular rounds like the 300 Winchester Magnum, 7mm Remington Magnum, and .338 Winchester Magnum. No-Go gages are sized to the maximum recommended headspace dimensions. If a rifle will chamber the no-go gage, it may still be within specifications, or this could indicate excessive headspace. Headspace standards are set by SAAMI (Sporting Arms and Ammunition Manufacturers Institute) specifications.
Excessive headspace can be dangerous as well as impair accuracy. Unsupported brass fired in a rifle action with excessive headspace can rupture, allowing gas to blow rearward like a rocket exhaust. This headspace gage is manufactured from top-quality, hardened steel and precision ground to American National Standards Institute SAAMI tolerances.
