.220 Swift (using Sierra bullets)
Date: Dec 15 2016
The .220 Swift was introduced by Winchester in 1935 and chambered in the Model 54 bolt-action rifle, but it was soon chambered in the newly introduced Model 70 rifle. It boasted of the highest velocities of any commercially available cartridge, with various factory loads easily exceeding 4,000 fps with 46-, 48- and 50-grain bullets.
Like many cartridges, the Swift received considerable criticism and praise, with some justification for both. The fact is that there were problems with early ammunition, cases and bullets, as well as the loading procedures of some handloaders. Period barrels were not as erosion resistant as today’s barrels with improved steels, so claims of short barrel life had some validity, but most of those problems have been resolved when using modern rifles, bullets and cases. With that said, not all varmint bullets will withstand the pressures, velocities and high bullet rotational speeds produced by the Swift. In developing the accompanying data (and additional data not contained herein) bullet breakup was experienced several times; bullets would appear as a cloud of “smoke” as close as 10 feet in front of the barrel, or as far out as 40 or 50 yards. When properly handloaded with the correct bullets and powder combinations, the .220 Swift offered accuracy and sensational results on varmints.
Today’s factory loads have changed. For reference, Federal Cartridge lists a 40-grain V-Shok bullet at a sizzling 4,250 fps, while Winchester lists a 50-grain softpoint at 3,870 fps and Remington a 50-grain softpoint at 3,780 fps (which is a transposed misprint according to a company representative). Hornady offers its 55-grain V-Max at 3,680 fps, while Nosler Custom lists a 50-grain bullet at 3,900 fps and a 60-grain at 3,550 fps.
All factory load velocities were duplicated or exceeded. Almost all .220 Swift rifles feature a one-turn in 14-inch barrel twist, as did the Ruger M77 test rifle. As such, they best stabilize bullets ranging in weight from 40 to 55 grains, with those weights consistently giving the best accuracy.