Skule me on neck tension

[user]

Should neck tension alone be sufficient to keep a bullet from pushing back into the case if I were to take a loaded round and push the bullet into a wood block?

Or, put another way, how hard should I have to push on a loaded 308 round to cause the bullet to colapse into the case if the neck tension is correct?

This is a bolt gun, not a sa.

Thank you

 

[Winchester 69]

Re: Skule me on neck tension

If you're firing single-shot, you only need enough neck tension to keep the bullet from falling out of the case. Shooting from a magazine is another situation. Bullets might be set back in the case by recoil. You have to measure the length of the rounds in the magazine, and then re-check the lengths after subsequent firings. If you have bullet setback you need more neck tension. Depends on the weight of the bullet, shape of the bullet, strength of the charge, and magazine capacity (number of previous firings).

 

[918v]

Re: Skule me on neck tension

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: user</div><div class="ubbcode-body">Should neck tension alone be sufficient to keep a bullet from pushing back into the case </div></div>

Yes.

You should not be able to move the bullet inside the neck using your hands and bodyweight.

 

[Grump]

Re: Skule me on neck tension

For me, sufficient neck tension will also keep the bullet in the neck if a round with no powder is attempted to be fired.

Even my .30 Carbine loads will do this. Pistol cases (other than Magnums, and that depends) are too small for that to work, though.

 

[Victor N TN]

Re: Skule me on neck tension

I don't think this is part of the original question. But I'll throw it out anyway.

Some powders need extra neck tension in the cartridge to get the powder to burn correctly. Ball powders that use graphite to control the burn rate come to mind right off. Sometimes you can check in the rifle and see a lot of unburned powder. That can be a clue that you have too little neck tension. It can also mean you are using a cheap powder.

I hope this helps.

 

[MitchAlsup]

Re: Skule me on neck tension

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: user</div><div class="ubbcode-body">Or, put another way, how hard should I have to push on a loaded 308 round to cause the bullet to colapse into the case if the neck tension is correct?</div></div>

Neck tension runs from zero through about 0.004.

Zero: For benchrest guns with fitted chambers, one can run with no neck tension whatsoever. Fire the cartrige, extract it, push the primer out, pop a primer back in, dump powder in, seat bullet by fingers and fire it again. For this to be acceptable, one needs the reloading station right next to the shooting range.

0.001: For benchrest guns where the shooting station is some distance from the reloading station and the bullet may be placed in any orrentation before being placed into the chamber.

0.002: For tactical bolt guns where the cartrige may have to suffer some minor abuse between the reloading station and the final firing position.

0.003: For tactical semi-auto guns where the bullet must suffer the slam bang loading cycle of the semi-automatic weapon. The nose of the bullet is rammed againist the feed ramp and then the cartrige is slammed into the chamber and stops abruptly on the sholder. You do not want the first bang to push teh bullet in nor do you want the abrupt stop to slide the bullet into the lands.

0.004: is for when you have a really nasty seim-auto slam bang cycle. However, in practice, after seating a bullet, the neck will yield and this has not more actual tension than the 0.003 above.

A neck tension of 0.002 will require 50-60 pounds of force to push a bullet into the case. The case must be supported, and you can feel the 3-ish pounds on your (20:1) lever arm as the bulet slides into the case. It is unlikely that you are strong enough to push a bullet into the case by hand or pull it out by hand without other tools.