On shake& bake full coated PC bullets the nose dia is increased the same amount as the shank is and if your chamber throat is short or tight to begin with it wont have clearance for the increase in size. Its a pain but you can remedy this by gripping the coated bullets before cooking with a pair of tweezers in a grease groove and just rubbing the bullet nose with your fingers to remove powder...or you could buy the electrostatic gun (about $120 at KMS tools) and with the bullets nose-down in a block, just coat the shanks.
Thank you for that.