What would cause my 336 35 Rem to let an extra round try exit the tube while chambering thereby causing gun jam as you close lever until push back in tube?

1. Worn or dirty magazine tube: If the magazine tube is worn or dirty, it can cause the rounds to not align properly with the chamber, which can lead to jamming. Clean the magazine tube and make sure that it is free of any obstructions.

2. Weak or broken magazine spring: The magazine spring is responsible for holding the rounds in place in the magazine tube. If the spring is weak or broken, it can allow the rounds to move around and cause jamming. Replace the magazine spring if necessary.

3. Damaged shell carrier: The shell carrier is the part of the gun that moves the rounds from the magazine tube into the chamber. If the shell carrier is damaged, it can cause the rounds to not be aligned properly with the chamber, which can lead to jamming. Inspect the shell carrier for any damage and replace if necessary.

4. Damaged extractor: The extractor is the part of the gun that pulls the spent casing out of the chamber. If the extractor is damaged, it can cause the spent casing to be stuck in the chamber, which can lead to jamming. Inspect the extractor for any damage and replace if necessary.