oh my. Go to www.saami.org, which will give you the standard bore diameters, or http://www.cip-bobp.org for the metricated.
22LR--.217
5.56--.219
308/300BLK--.300
7.62 x 39--.300
9mm parabellum--.346 sometimes .347
6/243--.237
6.5/264--.256
6.8/.270--.270
7/284--.277