Neck Tension

[NKBJ]

Do shorter or longer necks promote more consistent neck tension?

 

[Leadeye]

I know I need a lot more crimp to hold bullets in place with a 38-40 than the longer necked 44-40.

 

[patience0830]

When my neck has tension, I get a massage.

 

[bigedp51]

Do shorter or longer necks promote more consistent neck tension?

Bullet grip is controlled by how much smaller the case is sized smaller than bullet diameter. And also by the contact area of the neck on the bullet, and by brass spring back after sizing and expanding the case necks.

Ammunition for a semi-auto pistol does not rely on a roll crimp and the taper crimp is for streamlining the case mouth for feeding.

Example below is a Lyman type "M" expander for a .223/5.56 and has .003 bullet grip. And the RCBS AR Series dies have a taper crimp for case mouth streamlining and cartridge feeding.

Below a taper crimp on a 9mm cartridge to remove the case mouth belling, the bullet grip is controlled by the resized case diameter. This case is wasp waisted behind the bullet showing how much smaller the case was reduced in diameter than the bullet diameter.