Bumping headspace?

[USSR]

I couldn’t find anything on case headspace, dead space or real headspace in SAAMI’s glossary but I did find this and believe that this is what your referring to -

From SAAMI -


Quote:
HEAD CLEARANCE
The distance between the head of a fully seated cartridge or shell and the face of the breech bolt when the action is in the closed position. Commonly confused with headspace.

Bullet,

You won't find any reference to case headspace or some of the other terms that we are using here because, SAAMI doesn't deal with anything other than factory ammo in SAAMI spec chambers. Reloaders use the term and understand (for the most part) what is being said. And, No, head clearance is not being discussed here.

Don

 

[Bullet]

Sunray
Cartridges do not have headspace. Headspace is a firearm manufacturing tolerance only.

USSR

Sunray,

You continue to post this, knowing full well that excessive headspace or not enough headspace can be induced by the degree that the shoulder is bumped back. What is called "case headspace" is known and understood (or should be) by reloaders of bottleneck cartridges.
You also have excessive headspace when you have a rifle with perfect headspace dimensions and you bump the shoulder of your brass too far back, also resulting in a condition where the cartridge base to cartridge datum line (mid point in case shoulder) is too short for the chamber

I agree with Sunray
Cartridges, loaded or not, do not have headspace. Headspace is not created by the case but head clearance is and can be in or out of SAAMI spec.

 

[Walkalong]

Again, serious reloaders understand what is going on. You can play word games and do mental masturbation about it until the cows come home, but it won't change what is happening with the case and the way bumping it back to far creates artificial headspace, no matter what you want to call it.

Must be a lawyer type.

 

[Bullet]

Again, serious reloaders understand what is going on. You can play word games and do mental masturbation about it until the cows come home, but it won't change what is happening with the case and the way bumping it back to far creates artificial headspace,no matter what you want to call it.

If you want to call head clearance (headspace) go ahead but some reloaders might like to know the correct terms.

Either you get it or you don’t.

 

[USSR]

Bullet,

Again, we are not talking about head clearance. By your very own posted definition, "The distance between the head of a fully seated cartridge or shell and the face of the breech bolt when the action is in the closed position.", head clearance is the minute distance between the bolt face and the cartridge base. We are talking about the measurement from the bolt face or cartridge base to the midpoint (datum line) of the cartridge shoulder (a little more than 1 1/2 inches for a .308 Winchester). You really need to read up on this so you know what is being discussed here and can talk intelligently about it.

Don

 

[Bullet]

USSR
You also have excessive headspace when you have a rifle with perfect headspace dimensions and you bump the shoulder of your brass too far back, also resulting in a condition where the cartridge base to cartridge datum line (mid point in case shoulder) is too short for the chamber

In your example the case has been resized to short, creating extra space in the chamber. So where do you think the extra space is when a fully seated cartridge is in the chamber and the action is closed? I believe the extra space created is between the case head and the bolt face THE HEAD CLEARANCE. In your example I believe by sizing the case to much you’ve created excessive HEAD CLEARANCE not headspace. It is excessive head clearance that can cause casings to stretch and perhaps fail just above the web.
Cartridges, loaded or not, do not have headspace neither do cases. Headspace is not created by the case but head clearance is and can be in or out of SAAMI spec.

USSR
I think you need to do a little reading.
You might read this. These people are very intelligent -

http://www.benchrest.com/forums/showthread.php?t=47729&highlight=head+clearance


Some reloaders might like to know the correct terms.
I’m done.

.

 

[Walkalong]

Some reloaders might like to know the correct terms.
I’m done.

Done confusing the issue by getting anal about terminology when the point, which we are not missing, is for readers to understand what is going on, which is an artificially induced headspace problem.

And sure, there is a "head clearence" problem involved, but it ultimately boils down to the artificially induced headspace problem. Everybody understands a headspace problem.

Oh yea. Along with study, I learned much of my precision reloading skills by some of the folks who hang out at benchrest.com, and the folks who taught them.

Adios, see ya around on THR. Looking forward to your input.