neck thickness variations

[popper]

Thickness has little to do with neck tension, that is sizing. Effects centering in the bore.

[popper]

Thickness has little to do with neck tension, that is sizing. Effects centering in the bore.

[rebel]

Thickness has little to do with neck tension, that is sizing. Effects centering in the bore.

Now how can two pieces of brass and the same neck O.D but different I.Ds not effect tension?
Trust me, it will effect it and the pressure it takes to seat a bullet in the brass can be measured.


Google Wilson Force indicator Arbor Press.

[popper]

Uh, cause the neck thickness is close to the same all around .

[rebel]

Uh, cause the neck thickness is close to the same all around .

No, it is not. Many handloaders go to a great deal of trouble turning necks. Some, when using premium brass such as Lapua ,turn for concentricy or "clean up " the neck. I have seen material removed from one side and not the other. Cheaper brass is even worse.
If your brass is consistently perfect, please share a brand name so we can all go buy some.
There is no such thing as perfect brass unless you make it that way. "close to the same" is not a measurement.

https://www.accurateshooter.com/technic ... ng-basics/

http://bulletin.accurateshooter.com/201 ... hing-size/

Neck tension is a much misunderstood concept that can greatly affect accuracy. Once mastered, using the proper tools, it is a way to put the final "tune" on your load. Most don't think of the 300 Blk as a hyper accurate round. If you are loading for mag dumps or hunting you may not find this close attention to detail necessary. But you might be surprised at the level of accuracy gained by it.

[dellet]

Thickness has little to do with neck tension, that is sizing. Effects centering in the bore.

Now how can two pieces of brass and the same neck O.D but different I.Ds not effect tension?
Trust me, it will effect it and the pressure it takes to seat a bullet in the brass can be measured.


Google Wilson Force indicator Arbor Press.

Maybe popper can elaborate a bit, but I think this is what he meant and I would agree. You might be actually making the same point.

Neck thickness does not matter as much as hole diameter. The amount of interference fit. Example .002” than bullet diameter. That’s how tension is adjusted.

Uniforming necks basically does two things.

The first and probably the most important is center the bullet in the chamber and give it a straight start down the bore.

In the trueing of converted cases like the Blackout it also keeps neck tension linear instead of exponential, as you seat the bullet by not running the bullet down a tapered tube or hole.

[rebel]

If that is what he meant, then I agree wholeheartedly. It didn't read that way to me but Hell, I'm
wrong everyday - just ask my wife and daughter

[popper]

OK, fatigue strength of cartridge brass is 14K psi, yield is 17K psi. Neck tension is produced by
tension force of the cylinder of Cu - i.e. springiness. Basically INDEPENDANT of sample THICKNESS! Yes, more force is required to get that psi in a thicker sample but increasing a BO neck by 0.001"= 6E-6 square inches increase in surface area. I.e., no change in neck tension. It does make a difference at firing time. Lopsided brass doesn't center the bullet properly AND gets worse when base pressure is applied as the neck expands to fill the chamber. Neck expands because the base is squished and expands (bumped up). No bump up - gas cutting!
Neck tension is set by expander die, brass springiness and bullet BHN. Brass springiness does change with work hardening or annealing > when work hardened. But it is less ductile so our necks split. Neck turning just eliminates (as much as we can) neck lopsidedness.

[rebel]

Yes, I agree with that. Just lead off with that next time