Headspace issue

[Patrick Chadwick]

any chance he may have damaged the chamber ?

I doubt it. If he used the full weight of the flat of his hand to close the bolt, then he will have produced a force of half a ton to ton-magnitude on the gauge, which will not like it!
But even a ton is very little compared with the force produced by a full military load. The idiocy of such treatment of a gauge is, should he have succeeded in crushing the gauge only a couple of 1/1000", that gauge is now useless, as it has become shorter and will thus give a pessimistic indication for all subsequent chambers in which it is used. That is why, for me, the man has disqualified himself by his incompetent treatment of a precision tool.