Every gunsmith knows that proper use of a headspace gage is the most reliable way to test the length of a rifle chamber.

“Headspace” is the distance between the face of the breech and the base of the cartridge when the action is closed, and excessive headspace can be dangerous as well as impair accuracy. For instance, unsupported brass fired in a rifle action with excessive headspace can rupture, allowing gas to blow rearward like rocket exhaust. Because your safety is on the line, Forster Headspace Gages are made with painstaking care and exacting manufacturing standards to ensure accurate testing of your rifle’s chamber.

If a rifle closes on a GO gage, the rifle chamber will accept any ammunition that is made within SAAMI (industry standard) specifications. If a rifle closes on a NOGO gage, the rifle chamber might have excessive headspace. Most gunsmiths chamber a rifle’s headspace between the GO and NOGO dimensions. If a rifle closes on a FIELD gage, the rifle chamber is dangerously close to or already over the SAAMI specified maximum chamber size.

For additional calibers, see SAAMI Dimenseioned Headspace Gages (Rimless) or NATO Chamber Headspace Gages.


219 Donaldson Wasp, 219 Zipper, 22 Short, 22 Long, 22 LR Match, 22 Rimfire, 22 Savage Hi Pwr., 25-35 WCF, 257 STW, 257 Wby., 6.5 STW, 6.5 Rem. Mag., 264 Win., 270 Wby., 275 H&H, 7-30 Waters, 7mm Int. R, 7mm Rem. Mag., 7mm Wby. Mag., 7.62 x 54 Russian, 30 Herrett, 30-30 WCF, 30-338 Win. Mag., 30-378 Wby., 30-40 Krag, 300 H&H, 300 Mag, 300 Wby., 303 British, 303 Savage, 307 Win., 308 Norma Mag., 32 Win. Sp., 32-40 Ballard, 8mm Rem. Mag., 338 Win Mag., 340 Wby., 350 Rem. Mag., 356 Win., 358 STA, 375 H&H, 375 Win., 378 Wby., 38-55 WCF, 416 Rem., 416 Wby., 458 Win. Mag., 460 Lg Wby Mag




Sales Sheets
Reid Coffield demonstrates Forster Products Gunsmith Headspace Gages at YouTube.com
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