Neck tension

[Shooter13]

astly, I’ve recently found higher neck tension provides excellent and repeatable ignition and accuracy (0.004” plus)
Dave

For what? A bolt or AR?

 

[Dave M.]

For what? A bolt or AR?

F-open class bolt guns

 

[Firearmsunlimited]

Oh but it does.

The reason why it matters is that if you use very light neck tension then seat the bullet for any depth resulting in a hard jam the case will likely not hold the bullet in place but be moved by the lands. So your true seating depth might not be what you thought it was.

If you are only touching the lands or jumping your bullet then a light tension wouldn't matter as far as that issue is concerned.

If you have very light NT and the round is chambered and jammed deep enough and then you try to eject that round without firing - maybe you didn't size your brass correctly and it won't seat in the chamber, or you are in a match and they called cease fire, or a simple misfire, etc., then when you eject that case you will end up with a pulled bullet and a mess with your powder.

All I can tell you is to go to a national benchrest match and have one of the top shooter explain to you the mechanics of why they sometimes use a "deep jam" with light neck tension. I have seen Lester Bruno shoot a 25 grand jam. Clearly it would be impossible to jam a bullet into the lands that far. The intension is to in fact have the bullet slide back into the case neck.

 

[M-61]

I thought the OP switched from neck tension neck to shoulder bumping?
Correct terms and clear questions help to get proper answers
Maybe I misread so I’m done

 

[Dave M.]

With a .224 bullet and brass with .014 necks would you use .001 or .002 neck tension? Brass is new and I re-anneal after every 5 firings so spring back isn't a real concern.
Thanks

Bolt action? AR?
I’d use 2.5-3 thou neck tension min for an AR. For a bolt action you may find your rifle likes anything between 1-4 thou neck “tension”