If you have the budget, a good set of old school Mitutoyo dial calipers are the way go IMO; no batteries to fuss with.
I use these for general purpose reloading measurements within 0.001":
Amazing deals on this 6In Dial Caliper at Harbor Freight. Quality tools & low prices.
www.harborfreight.com
They're a cheap Chinese knockoff; I've checked mine against calibration standards and they do what they're advertised to do. Bear in mind, I reload for hunting/hobby; I'm not a competition/ or ultra long rangeshooter.
(corrected tolerance & link to caliper model in edit)