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case shape and accuracy

Posted: Thu Dec 17, 2015 11:49 am
by Tim N
Hi All,
Seems the smaller the bore size accuracy is better with a "short fat'' case eg from what I understand the 222 was the go to for short range bench rest for some time till the PPC arrived and BR.
When you go in the other direction to a bigger bore from what I can see this doesn't seem to apply?
Comparing a 280AI and the 7 saum there doesn't seem to be the jump in inherent accuracy as with the 222 to PPC?
Any thoughts on the matter?

Re: case shape and accuracy

Posted: Thu Dec 17, 2015 12:53 pm
by DaveMc
There are many that would argue that Tim. :D

Re: case shape and accuracy

Posted: Thu Dec 17, 2015 1:11 pm
by Norm
I think that the short fat case offers efficiency of burning and possibly lower ES because of this.
This may make them easier to tune?
Not sure if there are any other inbuilt accuracy advantages?

I think that other case features effect accuracy. I have found that a 6mmBR is easier to get accuracy from than a 6mm Dasher. I put this down to the longer neck of the BR case.

Re: case shape and accuracy

Posted: Thu Dec 17, 2015 3:35 pm
by Tim N
Well Dave that's what I was hoping for :D

Re: case shape and accuracy

Posted: Thu Dec 17, 2015 4:52 pm
by williada
Tim, there some who could make a stick shoot. I think that’s why Dave is smiling. True, burn efficiencies, neck length, barrel stiffness etc. all count, and the bigger you get the slower the powder you need, which is more finicky. Dare I say it Tim, but the case shape also sends a shockwave donut down the barrel peculiar to its shape as the pressure vessel in front of the bullet which the bullet interacts with. As we know some donuts taste better than others. :lol: