Home Forums Reloading Reloading Software QuickDESIGN Cartridge and Chamber Design Collision Question

I�m a new user to both QuickDESIGN (v1.05.00) and QuickLOAD (v3.5) software having owned both only since April 2009. I�ve just completed a search on QuickDESIGN to catch up on prior thread discussions but have not identified an answer to my question.

I�ve entered data in QD such that the cartridge drawing window indicated no collision points between cartridge and chamber dimensions believing this to be the correct design methodology.

However, when loading a QD� preloaded cartridge from the list - such as the Lapua Magnum, .375 Ruger, or the RUM cartridges - I find that the cartridge drawing window indicates the entire shoulder-angle from the shoulder to the shoulder-neck intersection is a collision area with an Error message indicating the cartridge will not chamber with less than _____ mm/inch headspace. There are no other collision points between cartridge and chamber dimensions.

My question is: �Is the correct methodology for design of cartridge and relating chamber dimension to assure no collision points between them except for the entire shoulder-angle from the shoulder to the shoulder-neck intersection?�

Thanks for your assistance.
Jim

You are right.
It is a shame that to-day developers of new cartridges violate the most primitive requirements of headspace design.

It began with the 30/06 and it's derivates: all their standard minimum dimensioned chambers do not chamber their maximum allowed cartridges if you have a gun with zero headspace !

I had just recently a short dispute with the developer of .17 Fireball, which shows the same flaw.
I got the answer: that is because the cases may last longer when being reloaded.

Normally this designed-in difference is for military cartridges who are slam-feed into the chamber. The slam-feeding is resizing the shoulder a little bit, so that after feeding the proper headspace is obtained.

But this is not true for bolt actions. With a rifle barrel and action set up for zero headspace you will encounter problems with maximum dimensioned cartridges while closing the action. Even when every component in use is showing standard dimensions.

And it is even more a shame that SAAMI and CIP accept this technical mishap.

Hartmut,
Thank you for your response and clarity of the issue.
Regards,
Jim