I have been pondering a theoretical question lately regarding the 6mm PPC and its inherent accuracy.

I wondered if there is somekind of physical harmony that exists in that cartridge that could be repeated in a scaled up version.
I mean, is there some relationship between bullet diameter, weight, powder charge, case capacity and size that all just WORKS, that could be scaled up to larger calibers of bullets?

I draft for a living so I drew up the 6ppc case and scaled it to have various larger bullet diameters and I don't see any currently made cases that have similar dimensions so it wouldn't be easy to test out this theory but I wondered if anyone has had similar thoughts?

Bennypapa

What about scaling up the 22PPC or 6BR? Both are very similar. Maybe one has the same relationships that coule be reproduced in a larger scale. (??)

Benny

It's been done! There are several wildcats that do just what you said. Accuracy is a function of a good barrel and good bullets and just about any design will work. Even the lowly 30-30 is capable of benchrest accuracy (see the 30 Aardvark as an example).

Ray

Cheechako...What cartridges in particular?


I do like the idea of necking up the 6br but that doesn't maintain the ratios between caliber and the other case dimensions.

To go from 6ppc to 7mm the case would be about

0.516" at the base
1.25" to a 30 degree shoulder @ 0.504"

oal about 1.75"

6br is the same base as the .308 win (0.473")

It seems that a fatter, shorter case would be needed.

Maybe I need to look over the short magnum cases.

Bennypapa

Benny-
.224"x 1.5= .336". Very close to .338. Is there a case that close to .22PPC or .22BR (x1.5)?

Just thinking out loud here.....with a head dia. of .473", enlarging the BR series by 50% would get you a case with a head dia of about .710" That's .600 OK class. I wonder what THAT would look like cut down and necked down to .338

Oh yeah- more ramblings; .244" (6mm) x1.5 = .366". Isn't that exactly the same dia as 9.3mm projectiles? Have someone turn some solids on a CNC lathe, get a long barrel with the right twist rate......

The guy with the .600 OK also turns bullets

quote:

Originally posted by Bennypapa:
Cheechako...What cartridges in particular?Bennypapa

Benny

The first that comes to mind is the 30 Myer. designed by George Myer in CO it is a Hunter Class benchrest cartridge using the 284 W brass or the 6.5/284 brass. It is a very accurate cartridge but no more than any of the other short fat Hunter cartridges. There is a 25 caliber also but I'd have to dig around to find the specs. Keep in mind that for any particular caliber there may not be an existing case that will result in exactly scaled up dimensions. The best to hope for is something close. But again, I don't think there is any magic case design out there. Don't forget, the 6 PPC was not the result of some calculated design. Lou Palmisano was using 220 swift brass but was having a hard time pushing the shoulder back and was also getting split necks with the original version of the PPC. He happened upon a box of 220 Russian brass and thought it would be a lot easier using it to make his cases. At that time it obviously wasn't even called the PPC, he called it the Eraser and it was a live varmint cartridge. He showed it to Ferris Pindell and the rest is history.

Ray

HMMMM
Looks like the 270WSSM would be the way to go.
Or a similar case design.

Great info, thanks!

Bennypapa

Something to keep in mind...regarding the 6PPC, one thing that makes it shine is good bullets! I've heard it said that a 25BR is a good relation to the 6PPC, but bullets keeps it from becoming a reality. The 30BR right now is a great shooter, it's accuracy is on par, literally, with a PPC. Plenty of good 30 light bullets available. But try to find GOOD 25cal bullets. Ray offers good advise, but when you talk accuracy, you gotta think bullets.

The other factor in the PPC's corner is that everyone and their buddy is shooting one in BR matches and nearly all conceivable problems have been dealt with. You can literally put together a rifle, load, brass prep, and loading procedure formula to make the rifle shoot lights out right from the start. With a lot of other cartridges that MAY have the same POTENTIAL, little work has been done and the experimenters are almost starting from scratch. While the potential may be there, the proven results aren't.

Gabe

RWS, i think, is leading in the right direction. From what I have seen,read etc, the 30br is really humming...literally. Little load development needed, no fiddling once optimum achieved, and ultra impressive barrel life. (One guy shooting a Kostchyen(sp?) barrel has 7000+ down the tube and still winning benchrest matches!) Check out 6br.com and look for the section about the 30br; I did and I am saving for the platform to build one up myself. Might give it a go in the long range dept, say....800 to 1k yds?