I agree with 209's misfire's are not common and most times a new cap will ignite the charge. Personally I never install my breech until I am ready to go, which always includes a few dry patches down the bore to ensure all excess oil is removed and then install the breech. I have NEVER had a misfire with doing it this way in terms of the first shot. As suggested make sure you hold the rifle in a safe position down range to ensure it isn't a delayed ignition for 1-2 minutes, then recap (upto 2 more times). If failure to ignite still exists, remove the breech, push from muzzle to breech and disgard.