Enfield Range Rifle question

[Son]

I don't have any references to quote for dating the bits, but I'd say they could be any time for the mid forties on to the sixties. This was the period which James Sweet was writing his booklets and selling his products.

The cigar cutter may be for gauging projectiles. The ammunition for competition was supplied by the army. Shooters would segregate it into lots by different ways to try to get the most consistancy possible. One example was by rim thickness, as variations could cause accuracy issues at longer ranges.
The tool you have looks like it could be set at a certain size to discard any rounds with slightly oversize or undersized projectiles.