Go to Harbor Freight and buy anyone of these Dial Calipers. They will be better than what it sounds like you have been working with.
https://www.harborfreight.com/6-in-dial-caliper-63730.htmlhttps://www.harborfreight.com/6-in-fractional-dial-caliper-63655.html?_br_psugg_q=dial+caliperhttps://www.harborfreight.com/6-in-dial-caliper-57445.htmlNow for pulling bullets there are several ways. The two easiest and cheapest are -- 1. If you have a reloading press. the cheapest way is go to Harbor Freight and buy an electrical wire stripper like this --
https://www.harborfreight.com/8-in-four-way-wire-crimperstripper-tool-63307.html ---
https://www.harborfreight.com/electrical-crimper-and-stripper-57595.htmlWith no die in the press put your bullet in the shell holder and raise it to the top of the stroke. The lead bullet should rise above the threads and to the top of the press. Then take the 'cheap wire stripper', spread them apart so that the teeth of the bottom section of the handles, that section that would strip different diameter wires are lined up around the lead bullet and the tool lays flat on the top of press. Squeeze the teeth into the lead (Only) but not real hard. Now while holding the handles in one hand use the other to slowly raise the press handle which will pull the casing from the lead bullet. Go real slow since they are loaded with powder.
Also, do not touch the press die threads or you may damage them.If your press stroke will not get the lead above the top of the press then go to this approach.
2. Buy an impact hammer from Amazon --
https://www.amazon.com/Impact-Bullet-Different-Expandable-Collets/dp/B07WDNH81Q/ref=sr_1_3?crid=19XQD7MD9PUR9&keywords=franklin+friction+bullet+puller&qid=1679522118&sprefix=frankland+friction+bullet+puller%2Caps%2C247&sr=8-3PS -- I had to use method #1 when method #2 would not remove the bullets.