Case Histories: 6mm PPC
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- Last updated: 15/12/2016
Wheelwrite looks at the history and development of the super accurate PPC family
In motor sport terms we’re looking at a Formula 1 cartridge this month. Fast, relatively flat, technical and mainly used to kill paper! Hardly the prettiest thing in the world it was the brainchild of the prolific American cartridge designing team of Ferris Pindell and Dr. Lou Palmisano. The rimless 6mm PPC, better known as the 6PPC, left their drawing board in 1975 and was an immediate ‘hit’ with the precision shooting fraternity.
From Russia With Changes
The family tree for this design started with the 7.62 x 39 Russian necked up to .243” diameter turned to length, loaded and fire-formed to give the distinctive 30° shoulder angle. However, the preferred donor conversion option is the more rugged Lapua .220 Russian case. Whilst the capacity is slightly reduced this is more than offset by its increased strength. There are two popular methods of fire forming. The first being a bullet-less method achieved by sealing a near case full of Bullseye or 700X with a wax closure and firing it to form the case. Alternatively the neck turn, trim and bullet fire method is used. Dedicated Bench Rest (BR) ammo-smiths often use a second barrel, cut with the same reamer as their match barrel in which to conduct the fire forming.
Although still regarded as a wildcat, commercial respectability arrived when dedicated cases were added to the inventory of Sako and Lapua, although largely shunned by the hard core BR shooters as being inferior to their fire-formed Lapua brass. Sako went one step further, producing a SAAMI listed 70gn 6PPC USA cartridge. Whilst it chambers in most of the small number of factory-produced 6PPC rifles, including Kimber, Cooper and the now defunct Sako 461 Vixen, it could never be competitive in BR although widely used as a varmint round. Maintaining the competitive edge means that custom dies and reamers rule the day. Their desired fit and form making factory ammo and chamberings uncompetitive. Furthermore, the need to intimately tailor ammo to the individual rifle and even to suit the weather conditions of the day makes this a handloaders speciality.
We’ve identified the winning brass for this cartridge. The remaining ingredients are less straightforward. Bullet choice can even vary with the weather conditions. Weights will be in the range of 60 – 70gns and will either be hand-made by the individual BR marksman or bought from custom makers such as Bart Sauter, Lester Bruno and Ronnie Cheek. Small rifle primers will be Match or BR from the popular makers. Propellant choice is, for some top shooters, a well kept secret, even decanting their choice into plain containers. Hodgdon Extreme Benchmark, H322 and Vihtavuori N133 seem to star, although Reloader 12 and Win 748 also get a mention. Top tooling is equally secretive. Tools from Wilson, Forster and Redding appear quite often. For the varmint reloader there are regular die products from Lee and RCBS amongst others.
This is arguably the most accurate ‘popular’ cartridge around. It in turn has spawned a multitude of super-Wildcats in the never ending search for the perfect cartridge. In the mean time the 6mmPPC can get you damned close to that one-hole, Holy Grail screamer!