Similar in appearance to 2nd Generation guns. 3rd Generation New Frontiers have five-digit serial numbers; 2nd Generation guns four-digit numbers. That and calibers offered are basically the only differences. 3rd Generations are chambered for .44 Special and .45 Colt and rarely found in .44-40. Barrel lengths 7.5" standard, with 4.75" and 5.5" rarely encountered. NOTE: Add 20 percent for .44-40; 35 percent for 4.75" barrel; 25 percent for 5.5" barrel.