12 gauge rubber

 is a type of 12 Gauge ammunition that appeared exclusively in Fallout Tactics.

This is the lowest type of 12 Gauge ammunition, use it only if you are left with nothing else.

Weapons using this ammunition

 * Beretta 470 Silverhawk
 * H&K CAWS
 * Ithaca Model 37
 * Neostead Combat SG
 * Pancor Jackhammer

Behind the scenes
The 12 Gauge Rubber was created for use in riot guns, and is designed to dissuade Chinese supporters from throwing things and breaking stuff. A hungry Deathclaw, however, is another matter entirely.