Well stated, but I think the guy lives in Franceicon and may not be able to acquire/import a correct A4 bolt.

If those who use HS gages read the instructions they will learn that the bolt has to close freely with no load applied. Receivers and Bolts are hardened, but the gages are hardened to a higher level, and as you say slamming the bolt on a gage when the bolt does not close freely has a chance to damage the receiver or bolt. If the bolt isnt stripped as it should be it is even more prone to damage. The ejector heat treated to an even lower hardness grade, if hardened at all (Ive not seen the an Ejector Drawing) as it needs to be more ductile by design.

For the record, slamming the bolt on a gage when the bolt does not close freely will not damage or alter the gage. It is not likely to cause the gage to be out of spec. I believe they are hardened to a high level and have to be so in order to function as a gage.