Address: The two common gages that were used in competition were 0.064 GO and 0.070 NO-GO; and keeping headspace on the tight side by selecting a bolt head that had the highest bolt handle position but still closed on the GO gage. The GO,NO GO and Field are made to SAMMI specifications. Many of then shooters have no idea the case has ruptured. Rare 1969 Underdog Rubber Springy Eraser Cereal Premium. Sort By: Reviewed in the United States on February 18, 2016, Very helpful customer service quality part, Reviewed in the United States on September 4, 2014. Was this page helpful? 303. British Headspace No-Go Gauge? : r/gunsmithing - Reddit Details Original issue Headspace Gauge, .303 British, MINIMUM, 1.63 mm (0.064 in.) 4 MK. NO-GO: Corresponds to the maximum headspace we recommend for gunsmiths chambering new bolt-action rifles. Find many great new & used options and get the best deals for 308 Winchester Headspace Gauge Set Go and No-go at the best online prices at eBay! If you shoot a lot and want to maximize case life, find a bolt head that gives you 0.064 or just slightly longer. 303 British Field Length Head Space Gauge - Midsouth Shooters Supply . Quote: First, headspace. The "field" measurement being the maximum allowable headspace measurement. 20): The National Military And Shoot, Arms And The Man Vol. $32.99 $ 32. XLVIII No. the respective national value-added tax, excl. Items in the Price Guide are obtained exclusively from licensors and partners solely for our members research needs. This is a British Armorer's gauge for use on .303 British rifles & Machine guns, such as the BREN & Vickers MGs.This gauge is NOT for use with the Pattern 14/P14 Enfield also called the Rifle #3 MK1, as it will damage the ring around the bolt face.These have some light surface rust from storage.The gauge is dated in the 1950's.The gauge is set & marked to Commonwealth Military Standards, NOT SAMMI.CIP/British Military standards refer to this gauge as"GO".