Introduced in 2004, the 204 Ruger is a high-performance varmint round well suited for use where long shots and abundant targets exist. It launches 32- and 40-grain bullets fast enough to come close to matching 22-250 Rem trajectory with 40- and 55-grain bullets but with significantly less recoil and barrel heating. As a factory combination for use against Prairie dogs and similar species, the 204 Ruger is hard to beat. With the best handloads using a well-tuned load, it will take vermin past 500 yards, which is much farther than most of us can expect to make solid hits most of the time. Based upon the 222 Rem Mag case, this round has similar usable capacity as the 5/35 SMc, which is chambered by Savage in its Custom Shop but lacks commercial ammunition availability. With a superior case design and higher working pressure, the 5/35 delivers about 250-fps higher velocity with the same bullets and with identical barrel heating — design matters! In most situations, the 204 leaves the varmint hunter wanting for nothing. As with any high-performance round, barrel heating is a significant concern. Allowing plenty of time for barrel cooling can significantly increase barrel life. Conversely, overheating the barrel by rapid firing can render a barrel uselessly inaccurate after surprisingly few shots. The heritage of this case dates to the 38 Colt cartridge of the 1860s and before that with the 1839 introduction of the 36 Colt Paterson cap-and-ball Revolver.