Donavon a set of blade mikes are more precise then a set of regular mikes bar none .+1 ..... exactly !.!.!
All that is needed to be measured is the widest part of the brass (near the base/web/.200-line of course) both "before sizing" and "after sizing". It does not take a "blade mic" to get those measurements, and I prefer a micrometer over a blade mic myself, because a micrometer can more accurately find the widest part, verses a blade mic having to be pin pointed on a location for measure, which can lead to error.
A caliper can work as well, but a micrometer is the best measuring tool for the job.
Donovan