i have found that using a hand held priming tool gives good sense of feel for the primer bottoming out in the case. a quick way to verify if primer is fully seated is to run your finger or thumb nail across the case bottom; if the primer feels like it is above the case, a "high primer" condition exists. just put the case back in the tool to seat a little deeper. i have experienced a very tight fit on some new cases when installing primers. a little dry moly lube on a q-tip will make them seat much more easily. good luck! reloading is great fun.