The 6mm PPC-USA By Chuck Hawks The 6mm PPC was designed in 1975 by Ferris Pindell and Louis Palmisano for bench rest shooting. PPC stands for Pindell-Palmisano Cartridge. It was based on a necked-up and fireformed .220 Russian case (another target round). The 6mm PPC is a very stubby round, with a case only 1.503 inch long and a rim diameter of .445 inch. The shoulder angle is 30 degrees. The case uses small rifle primers. There is no standard cartridge overall length for the 6mm PPC, which uses standard .243 inch diameter bullets. 60-70 grain match bullets are typically used for competition in bench rest rifles. Their greater resistance to crosswinds gives the 6mm bullets an advantage over the lighter bullets used in the .22 BR cartridges. The 6mm PPC was designed specifically for use in bolt action single shot rifles. It is not well suited for use in repeating rifles due to its very short, sharp shouldered case, which makes for serious feeding problems. It is often impossible to get the 6mm PPC to feed from the magazine of even a custom made bolt action rifle. Its use should be confined to single shot rifles. Norma of Sweden and Sako of Finland supply 6mm PPC brass for handloaders, and Sako chambers rifles for the cartridge. The letters "USA" were added to the designation "6mm PPC" at the request of Louis Palmisano when Sako standardized the cartridge in 1985. Sako offers a factory load using a 70 grain HPBT Match bullet at a MV of 3200 fps and ME of 1481 ft. lbs. At 200 yards the Sako figures are 2407 fps and 892 ft. lbs. Sako ballistic tables show the following trajectory for this load: +1.5 inches at 100 yards, 0 at 200 yards, -7.2 inches at 300 yards. This Sako factory load is typical of bench rest loads for the 6mm PPC. Handloaders can duplicate the ballistics of either using similar HPBT match bullets at MV's in the 3100-3200 fps range. Most reloading manuals have loading data for the 6mm PPC. The Nosler Reloading Guide #5 shows that their 55 grain Ballistic Tip varmint bullet can be driven to MV of 3348 fps with a maximum load of 28.5 grains of H322 powder. The 70 grain Ballistic Tip varmint bullet in front of 25.5 grains of H322 delivered a MV of 3088 fps. Nosler technicians found H322 to be the most accurate powder with both bullet weights; test barrel length was 22 inches. The Nosler trajectory tables show the following for a 55 grain bullet at 3300 fps: +1.3 inches at 100 yards, 0 at 200 yards, and -6.4 inches at 300 yards. The following information for heavier bullets is taken from the Speer Reloading Manual #13. The Speer test rifle had a 1-12 inch twist barrel. The 85 grain Speer BT spitzer bullet can be driven to a MV of 2703 fps with 25.5 grains of H335, or 3156 fps with 29.5 grains of the same powder. The 90 grain Speer Hot-Cor spitzer bullet can be driven to a MV of 2601 fps with 25.0 grains or 3031 fps with 29.0 grains of H335. The Speer 90 grain Hot-Cor spitzer bullet has a trajectory like this at a MV of 2900 fps: +1.9 inches at 100 yards, 0 at 200 yards, -7.7 inches at 300 yards. Note: An article about the 6mm PPC and 6mm BR Rem. can be found on the Rifle Cartridge Page. |
Copyright 2005, 2013 by Chuck Hawks. All rights reserved.
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