I am glad that a company like this is in existence to give vintage shotguns that would be otherwise deemed unsafe with modern loads, a second life. Functionality of the these ultralight 20ga shells was stellar and was expected given my experience with RSTs 12ga Falcon. My shooting skill with a newly bought Marlin 31-20 (yes, I'm aware of the blanket recalls and had the little Marlin checked by a gunsmith) however?????? Much to be desired. I have recently bought three more boxes in anticipation of the 2nd week of South Texas White-wing season. If you have a vintage 20 get it checked by a gunsmith and feel safe using these low pressure shells.