Neck Tension?

[Swan]

Just curious who has experimented with different neck tensions on the <span style="font-weight: bold">same</span> load, and what differing results were observed? If any. Since a lot of us use the Redding bushing dies or some variant I imagine I'm not the only one curious?

 

[Victor N TN]

Re: Neck Tension?

I have experimented from loose enough to push the bullet in with my bare thumb to so tight it shaves metal off the bullet jacket. A lot depends on the specific powder you're using. But most loads will like a medium tension that holds the bullet in place until the powder collumn has good ignition. The pressure of the burn will help the powder to burn better in most instances. But too much neck tension can cause a bad reaction as well. Having a known rifle, scope, ammo and shooter are the only way to know what changes what. And only change one variable at a time.

 

[BOLTRIPPER]

Re: Neck Tension?

me thinks...all things being equal (perfect powder charges,polished necks,)....that seating depth is where you may see some variance....and if your bullet likes to be jammed or jumps.....makes a huge difference....but you already know that

 

[Swan]

Re: Neck Tension?

I kinda figured seating depth would be a larger factor, and is what I am experimenting with now. It seems the slightest variance with the 155 Scenars makes a big difference.

 

[rksimple]

Re: Neck Tension?

I ran .002 NT with the 155s seated about .020 off the lands. It worked OK. Tried .001 NT and no difference. After trying the new 2156 SMK, don't think I'm going to use the scenars anymore. The SMKs are more forgiving of everything.

 

[dar1246]

Re: Neck Tension?

I also like the .002NT. I don't think I would go any less than that. If you are running and gunning I wouldn't do that. If you are shooting matches, it might be something to play with.

Sometimes if the gun is shooting great. You end up chasing your own tail trying for the ultimate load. I'am as quality as anybody for this.

 

[Greg Langelius *]

Re: Neck Tension?

I don't have/use neck bushing dies. I make an effort to control neck tension by another means, using the expander ball and conventional dies.

I back off the sizer die so it only sizes down the end part of the neck length.

By varying the amount of neck length that gets resized down, I can increase or decrease the amount of grip the neck applies to the bullet.

FWIW, I find that resizing the last 1/16" or so works pretty well for me.

Now obviously, this has additional consequences.

Shoulders don't get bumped. The cases are .260 Rem. I find that I can use a .308 die as a bump-only die.

Bases don't get resized. I find that the bases expand once, maybe twice, then don't expand any more. The cases don't pose any chambering or extraction problems, and inside 'finger' tracing detects no internal case anomalies. At this point I can't find any negative consequences to leaving the bases expanded. It may even be beneficial, as it subjects the case walls to a lot less work hardening. In any case, they do get resized on those rare occasions when I need to bump the shoulders.

Greg

 

[Sig685]

Re: Neck Tension?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Swan</div><div class="ubbcode-body">Just curious who has experimented with different neck tensions on the <span style="font-weight: bold">same</span> load, and what differing results were observed? If any. Since a lot of us use the Redding bushing dies or some variant I imagine I'm not the only one curious?
</div></div>

Testing to see if adjusting the neck tension at different levels probably ranks about as low as it's possible to be on the importance to accuracy. What is extremely important is to have CONSISTENT neck tension, whatever you decide is best for your needs. For that I use Redding bushing dies and I have specific bushings for different headstamp so as to provide the same neck tension irrespective of the case.