So I'm reloading some 6.5 creedmoor with 140gn RDF and Hornady brass with the Forster Ultra micrometer seating die on an RCBS Rockchucker. Before loading I measure each bullet from base to ojive. So for example all are .784. Now my loaded round I want to be .050 off lands which gives me a measurement in my rifle of 2.236. Now I set up the first round and get the micrometer set to seat to 2.236. Next bullet I seat it may be 2.250. Next could be 2.245. Why then if I set up the first round to seat at the depth I want, the next ones are no where near that measurement? It seams every bullet I seat I have to check and reset the seater die?