Cartridge won't feed into chamber

1. Overall length too long. See loading manual for dimensions.
2.  Improper headspace. See loading  manual for dimensions. Use headspace case gage.

 3. Too much bell left on case. (Not enough crimp.)
4. Case buckled.
  a. Too much crimp.
5. Using brass that has been fired in an oversize chamber.
6.  Gun operation problems.

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