I got 2 headspace-gauges for 7,92x57mm. The two gauges showed the marking “ G.98. “ and the numbers 2,85 or 2,60. In addition to the numbers, there are two letters which could be the first letters of the name of the manufacturer of these gauges. This two letter could possibly be read as FD or ID. There are no acceptance-marks visible. I compared the inscription with the inscription of a gauge which was used in a Bavarian Weapons-factory. The stile of the letters looked very similar. This gauge also showed the marking “G98”, which I interpret as the short form of “Gewehr 98”.
Could anyone give some more information about these gauges and the inscriptions?