The investigative lead generated by recovering a microstamped bullet from a crime scene would be between a crime-related bullet and its purchaser; as is true with a national RBID, this stops short of directly linking ballistics evidence to the particular person who fired the shot. Moreover, in complex crime scenes where multiple firearms are discharged, microstamped bullet markings could not directly lead to connections between specific bullets and the guns that fired them.

Though individual records would be much simpler than in an image database, ammunition microstamping would require a new database of massive scope, providing the mapping from codes on individual rounds of ammunition to the code on the box of ammunition that contained them. This new database would rely on collection from ammunition manufacturers and would grow by billions of records (one per piece of ammunition) each year.

In the discussion of ammunition microstamping in California, a perceived advantage was that the second critical data-gathering activity—logging the ammunition box codes at the point of sale—would require little or no new resources. Because the technical infrastructure to scan both ammunition-box barcodes and the barcodes on purchasers’ driver’s licenses is already in place among the state’s ammunition vendors. However, in other states, barcode reading and ammunition sales databases may not be standard, and practices for examining or recording driver’s license or firearm owner’s identification card information may also vary. In such states, a new system would have to be developed to capture codes at the point of sale.

As is the case with firearms microstamping, cost estimates vary widely, and the inability to peg down a per-unit cost factored into the inability to pass the California legislation. In terms of initial capital costs to ammunition manufacturers, Ammunition Coding System stipulated that “reliable estimates for a complete set of engraving/material handling equipment range from $300,000 to $500,000 each.” However, “since approximately 10 billion bullets are sold in the United States alone each year, equipment costs, once amortized over the number of bullets produced and sold are not significant” (http://www.ammocoding.com [February 2008]). While proponents of microstamping argued that the per-bullet cost would amount to 1 cent or less, ammunition manufacturers countered that the per-unit cost would be measured in dollars (Yamamura, 2005b). A further sticking point in the California legislation was the provision for a licensing fee—per round of ammunition—to be paid, in addition to the cost of making the laser engravings. Research on the costs associated with retooling existing manufacturing plants would have to be conducted as a supplement