In the January 2012 issue, in captions accompanying two articles, Concealment Index is mentioned but not adequately defined. For example, on page 35, one caption reads: “The CI is determined by combining the overall length and height of a pistol.” But combined how? Based on the length and height of the Sig P239 under discussion, it is not the sum, not the difference, and neither product nor quotient. How about giving us readers an operational definition that defines how to perform the measurement?
— David Koch
From the instructions we give our writers: “Measure the concealability index by stretching your measuring tape from the center of the muzzle, along the top of the slide, down the backstrap and finally along to the front edge of the grip in front of the magazine’s baseplate. Measure with the magazine in place. Don’t allow the measuring tape to conform to the gun’s curves for this measurement; pull it snug.” This measurement, while not strictly scientific, does give us a single standard of comparison between different gun shapes. The lower the number, the easier it will be to conceal the firearm.