Quote:
Originally Posted by
MOD 70 
| The ppc line of benchrest cartridges are actually based on the 220 Russian case.
Very good question regarding the sharp-shouldered cases! I`ve never seen anything about it either except to try to increase case capacity very slightly.My guess is that the inherent accuracy these cases seem to have is because these are generally hand-loaded wildcats.They are almost always fire-formed and then only neck-sized resulting in optimum case to chamber tolerances and perfectly controlled headspace.To add the icing on the cake,these cartridges will normally see a custom tailored hand-load ideally suited to that individual rifle.Sound reasonable? |
The 220 russian parent case is the 7.62x39 so I guess I should have said 6mm ppc's grandparent case, LOL.
Your explaination of the accuracy of sharp shouldered cases makes sense only that .308 stock ammo is also more inherently accurate than let's say the 17 degree angle 30-06. I've read that the .308/7mm-08/.243 are more accurate
because of the stout , sharp shouldered case but not
why the case made such a difference. There also seems to be a limit to the advantage as well because we are now seeing that short magnums are not a real advantage in the accuracy area even though they share the characteristics of the case with inherently accurate cartridges.
There is, of couse, other good reasons for using the short, fat cartridge it would be more "efficient" than the traditional long, narrow cartridge, as more of the powder column would be in the immediate vicinity of the primer as it detonated.. maybe the even powder burn helps accaracy..??
Maybe the headspacing is more accurate on even "stock" rifles with the stout case/caliber..??
I've read things that have eluded to this but no proof as of yet.
