Is there any data available about tight necks that pinch bullets causing pressure spikes?

You may find Geoff Kobe's "The Report" at

www.border-barrels.com

to be of interest for you.

yes there is a difference in pressure but it is pretty insignificant when reloading below max...

I use undersize by .004 the expander balls on all my big bore rifle reloading dies in order to minimize bullet set back in the magazine, when combined with full case powder charges to be able to omit the crimp, mostly in double rifles..but also to utilize a lighter crimp in bolt guns...

------------------
Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

1) I have increased the powder charge until the case fails in 22 calibers. I know that slope of change in pressure effects.

2) I have increased the bullet size until it is much bigger that the bore, and per Ackley, have never seen any change in pressure effects.

3) I have used .308 brass necked down to .243 causing thick necks causing a pinched bullet casusing horrendous changes in pressure. The amount of change in case neck as small as .003" I have seen to double the diameter of the primer pocket.

The third effect is what I am asking about. Someone said there was an American Rifleman article long ago about it.

Thanks for any resourse you know about.

That was interesting reading the Border Barrel site.

[This message has been edited by Clark (edited 03-24-2002).]