Hi Philip--
The Model of 1917 Enfield did not have an armorer's test bolt from what I have been able to ascertain. They had have a test fixture which tested the bolt. The fixture comprised of a spare receiver with a tool (Tool engineering drawing 412234) and dial indicator screwed into the receiver in place of the barrel. The bolt to be tested would be placed into the receiver with the dial indicator set at 0. If the dial indicator read more than .001 the bolt would be rejected. I hope this was helpful. The information came from the Base Shop Data manual for the 1917 Enfield dated 2-11-1943.
--fjruple