The elements of an Accurate Cartridge

[Grimstod]

I think a dasher or a brx is about the same class for mid and long range as a ppc is for short . Larry

I would have to agree. Maybe not quite as accurate as the PPC but they are very close. There advantage is the ability to buck the wind. Now if only Lapua would make a BRX with a neck that is .1in longer.

 

[ebb]

A lot of your statements are more about convenience rather than accuracy. If you had an accurate case that had excessive brass flow you would just have to trim it more often, it could still be very accurate. Maybe a better title could be elements of a user friendly accurate cartridge. chasing the lands , thick base to keep pockets tight, many reloads on cases, ability to fit standard actions and other points just make a convenient case to shoot (reduce the amount of work involved) and have little to do with pure accuracy. Many of the pioneers of benchrest had none of these creature comforts yet had accurate rifles just the same.

 

[dcali]

1 You should care about brass flow. It means more trimming and that reduces the amount of brass you have in the case itself. Thus changing the way it shoots. If you have a lot it will not be as exactly consistent from shot to shot.

2 I was talking about seating it below this area. Doing so makes you vulnerable to the dreaded doughnut. And that is just plain bad for accuracy period.

I like your thoughts on the PPC base size. I think lengthening it has been tried though. Check out the 6AR I think it has same capacity as the 6BR but could be mistaken. Most say though that the 6PPC is accurate because the of the case proportions. Not the base size. Then again though we really do not know why its accurate. All the things I listed though do fit its description though.

[/QUOTE]

I was not aware of the 6AR. That looks to be exactly what I'm talking about. (seems wasted in an AR, but that's another topic) It wouldn't surprise me if it's inferior to the PPC up close (the PPC seems to have been pretty well optimized for short range BR over the years), but perhaps it's a better mid range cartridge than the 6BR. In any case, it'd be interesting to see if there's a difference. Might be fun to see how an even longer version does. Basically, I wish I had the time and money to do a more careful study about how case geometry really impacts inherent accuracy. You could make three cases with identical volumes, but different case heads, shoot the same bullets and see what you get in terms of consistency of velocity, powder choices, etc.

 

[Grimstod]

A lot of your statements are more about convenience rather than accuracy. If you had an accurate case that had excessive brass flow you would just have to trim it more often, it could still be very accurate. Maybe a better title could be elements of a user friendly accurate cartridge. chasing the lands , thick base to keep pockets tight, many reloads on cases, ability to fit standard actions and other points just make a convenient case to shoot (reduce the amount of work involved) and have little to do with pure accuracy. Many of the pioneers of benchrest had none of these creature comforts yet had accurate rifles just the same.

Convenience does make for fewer room for mistakes.

 

[R.Morehouse]

I think it is what ever Bob ( The Viper ) Pastor has been shooting and winning with for all these years.........Same gun same round loaded the same way......Using Bob C.'s 141's.................

 

[Grimstod]

I was not aware of the 6AR. That looks to be exactly what I'm talking about. (seems wasted in an AR, but that's another topic) It wouldn't surprise me if it's inferior to the PPC up close (the PPC seems to have been pretty well optimized for short range BR over the years), but perhaps it's a better mid range cartridge than the 6BR. In any case, it'd be interesting to see if there's a difference. Might be fun to see how an even longer version does. Basically, I wish I had the time and money to do a more careful study about how case geometry really impacts inherent accuracy. You could make three cases with identical volumes, but different case heads, shoot the same bullets and see what you get in terms of consistency of velocity, powder choices, etc.[/QUOTE]
Yes check it out. It has a very short neck though. Ill put a photo in.

 

[KMart]

I was not aware of the 6AR. That looks to be exactly what I'm talking about. (seems wasted in an AR, but that's another topic) It wouldn't surprise me if it's inferior to the PPC up close (the PPC seems to have been pretty well optimized for short range BR over the years), but perhaps it's a better mid range cartridge than the 6BR. In any case, it'd be interesting to see if there's a difference. Might be fun to see how an even longer version does. Basically, I wish I had the time and money to do a more careful study about how case geometry really impacts inherent accuracy. You could make three cases with identical volumes, but different case heads, shoot the same bullets and see what you get in terms of consistency of velocity, powder choices, etc.

Yes check it out. It has a very short neck though. Ill put a photo in.

[/QUOTE]


Take a look here
http://forum.accurateshooter.com/threads/6mm-grinch-defeats-entire-field-of-6ppcs.3912901/

This seems to be the area that Bart is working now. The 6 Grinch and the 6mmAR turbo are quite similar

 

[dcali]

That makes a lot of sense to me, and I expect that it works out to be a very capable 600 yard round. The neck is a bit short - it looks like a parent case with an extra 50 thous of length would help a lot.