Gene
What do you think contributes to the dominance the 6PPC has had for group shooters over the last 25 years. Can you give physical characteristics that make it the cartridge that a vast amount of shooters choose for their short range BR gun.
Stephen Perry
Angeles BR
Steve,
There are a number of reasons the 6PPC cartridge dominates short range benchrest. One is the fact that the Sporter category requires a bullet larger than .224. The obvious choice; a 6mm/.243.
When the PPC was in the planning stages, the goal was to drive 68 grain 6mm bullets at 3200 fps using 322, 748, and other such powders. By 'improving' the 220 Russian case, internal capacity was increased by approximately two grains and the rest is history.
The 22PPC proved overbore and its full potential as a benchrest round was not realized until shooters began shortening it by .080 to .125.
The case capacity of the 6PPC proved ideal when used with the powders of the day and shooters were quick to realize that with one 6PPC Sporter, they could compete heads up in all three bag gun categories. For many years there was little experimentation with other cartridges.
Some believe there is something magic about the 6PPC and that if you change ANYTHING the magic will be lost. Nonsense! The 6PPC is nothing more than an 'improved' 220 Russian, necked up to 6mm. There is no magic in a 30 degree shoulder or minimum taper body.
Parker O. Ackley was responsible for introducing the shooting world to the so called 'improved' cartridges. His case design called for a .010 per inch taper in the body and a 40 degree shoulder. With the exception of the 30 degree shoulder, the PPC cartridge is nothing more than an Ackley improved 220 Russian.
It is no secret that I do not favor 'improving' standard cartridges. This is a personal opinion but I don't like the look and I don't like the feeding problems associated with such rounds. It would be hard to describe, but some things just 'look right.' I'll never forget a friends comment when I first showed him the no-turn 220 Beggs cartridge. He's an old cowboy; raised on a ranch near Uvalde, TX and now flies the Airbus A320 for US Airways. He held the little round up and said, "Cute lil' cotridge."
The original 220 Russian case from which the PPC was developed was made by Sako. It was a balloon head design and would not withstand anywhere near the pressures we use today with the Lapua case. Once the supply of original Sako cases dried up, there was a period of time in which brass was hard to find and some were charging as much as $3.00 to $4.00 a piece.
Enter the Sako 6PPC USA case.
For a time, Sako made the 6PPC USA case that required no preparation other than neck turning. They were good cases and very convenient to use but they introduced a problem that plagues us even today. The original Sako 220 Russian case measured .4380 right in front of the extractor groove and all of the original reamers for the PPC were ground for that dimension. The Sako 6PPC USA case measured .4410. This caused a lot of problems for a few years and even today we still find chambers that measure 4380 to 4390 at the pressure ring.
Most commercial sizing dies are designed for the 6PPC USA case. They may or may not work with the 6PPC made from the Lapua brand 220 Russian case which measures 4400 at the pressure ring. It all depends on the reamer. My 6PPC reamer measures 4430 at the pressure ring and 4310 at the shoulder.
When I began teaching benchrest, I encountered so many mismatches between chamber and die, I decided to develope my own line of cartridges with standardized chambers, sizing and seater dies. The 220 and 6mm Beggs cartridges have proven themselves the equal of anything in use on the 100/200 yard firing line. The 6Beggs now holds the unlimited record for five shots at 300 yards, .355 set by Jim McGowin this year at St Louis.
When the Lapua 220 Russian case was introduced, it opened up a whole new world to the benchrest crowd. It is so well made it is in a class by itself and withstands pressures far in excess of the norm. The Lapua 220 Russian case was chosen as the basis for the 220 and 6mm Beggs cartridges. The only change being the radius at the junction of the neck and shoulder. The standard 220 Russian chamber uses a .125 radius at this point; the Beggs chamber, .060. The Beggs cartridge holds two grains less powder than the PPC but generates the same velocity. Accuracy is limited only by the quality of barrels and bullets.
With the powders of today, there is no need to 'improve' the Lapua 220 Russian case; it's perfect just as it comes from the box. With its 21.5 degree shoulder and .040 body taper, it feeds and extracts like butter.
In view of the fact that the Beggs cartridge holds two grains less powder than the PPC many have expressed concerns about muzzle velocity. In the 220 Beggs with 52 grain bullets, from a 22 inch barrel, my standard load of Hodgdon's Benchmark produces 3615. My standard load of Hodgdon's H4198 in the 6 Beggs using 68 grain bullets averages 3360 and I can easily get 3400. I think that's adequate; don't you?
Later,
Gene Beggs