RE: Iowa Gobbler...
You had the chamber closed - ifitwere openthe trigger sear would not have released and it wouldn't have clicked.
Youmayneed to replace your firing pin and/or spring.Did you take a look at the primeron the rounds that didn't fire? If the primer is only slightly indented, or not indented at all, you most likely have a firing pin issue. That is easily fixed.
I would advise youto shoot those shells that didn't fire in another gun to rule out ammo issues (highly unlikely that multiple shells are bad). If those shells go boom in another gun then your problem lies in your 1300. A good gunsmith can then figure out what your problem is and fix it in short order.
Mouthcaller