My results told me that I’d could fill the M500 with 3-inch 000 Buck, put it in the corner next to my pillow, and be surrounded by a warm and fuzzy feeling. All five 000 pellets consistently fell in a 5-inch circle from 10 to 20 feet; some patterns vertical, some horizontal. Still, all were within 5 inches, providing a good margin for aiming error, yet not so wide to allow holes in the pattern through which a Bad Guy might slip through. The 000 load fully penetrated both the ½-inch OSB and the 1-1/2-inch fir board, with what I would consider exceptional deformation in the recovered copper-plated pellets. Deformation in lead pellets means expansion, and expansion translates into increased shock in the form of transferred kinetic energy, as well as upgraded on-target trauma. The copper plating provides a hardness factor, without nullifying the capability of the pellets to deform. A “controlled expansion,” as the bullet guys say.