'Rev.e': Welcome to the KCA Forum.

Your description does not clearly communicate the multiple problems you are reporting or provide possible clues.

1. Did the cartridges that failed to fire have a strong firing pin indentation on their primers?

2. Magazine feed problems are often caused by dirt, dried grease, rust and crud restricting the movement of parts.

3. If you post some clear, close-up, detailed photos of your sight and other questionable areas, you will get better analysis of possible problems.