How much neck tension ?

[DLT]

I have a redding non bushing full length sizer. Using my adg brass annealing after every firing and using the expander ball, my necks come out consistently .270. Loaded rounds measure .271 I took the expander ball out and the necks came out of the die measuring .268 which gives .003 neck tension and that’s as small as I can go. I figure most run between between .001 and .003 tension. Most of my other full length dies will have .002 neck tension but it’s rough coming back through the neck with the exp ball meaning the die is closing the neck down way too much. I bought a mandrel die body from 21st century with the appropriate size and it came in .001 undersized what it’s marked so I can’t test any improvements using it

 

[Bill Norris]

Neck tension is pretty much like every other aspect of load development. Each rifle will have it's own little likes and dislikes as well. Testing is the only way to know exactly what your rifle will shoot best with.

 

[DLT]

Neck tension is pretty much like every other aspect of load development. Each rifle will have it's own little likes and dislikes as well. Testing is the only way to know exactly what your rifle will shoot best with.

I thought I was going to try and set neck tension with different sized mandrels which I guess I still can I’ll just be limited because of no smaller than my die is sizing the necks.

 

[Bill Norris]

I thought I was going to try and set neck tension with different sized mandrels which I guess I still can I’ll just be limited because of no smaller than my die is sizing the necks.

Right I understand. It's really hard to get the full story with limitations no doubt.

 

[Straightshooter1]

I have a redding non bushing full length sizer. Using my adg brass annealing after every firing and using the expander ball, my necks come out consistently .270. Loaded rounds measure .271 I took the expander ball out and the necks came out of the die measuring .268 which gives .003 neck tension and that’s as small as I can go. I figure most run between between .001 and .003 tension. Most of my other full length dies will have .002 neck tension but it’s rough coming back through the neck with the exp ball meaning the die is closing the neck down way too much. I bought a mandrel die body from 21st century with the appropriate size and it came in .001 undersized what it’s marked so I can’t test any improvements using it

If you don't like the sizing die closing the neck down so much, you can always have it reamed to the specification you want??? Of course, that means you may have to have different size expander balls to get the neck tension you want.

 

[Kracken McGraw]

Polish your expander ball a little so it doesn’t open the neck as much.

 

[DLT]

If you don't like the sizing die closing the neck down so much, you can always have it reamed to the specification you want??? Of course, that means you may have to have different size expander balls to get the neck tension you want.

I think it’s closing enough. It’s not not closing near enough like my other dies have in the past. This one is barely working it which is a good thing Using the expander ball gets me .001. Not using it all all gets me .003. I have dies that without the expander ball it will ruin a bullet trying to seat

 

[Link]

I hate pulling the expander ball back through the neck. Buy I don't shoot well either lol.

 

[Sandstorm]

I use bushing die's and a Mandrel ( No expander ball at all )
It works for me and it may work for you.

 

[nakneker]

I use bushing die's and a Mandrel ( No expander ball at all )
It works for me and it may work for you.

That’s what I’ve been doing the last couple years for about half of my rifles with great results.

 

[DHD]

Bull Norris' comment was a good one and to add to it, how does the rifle shoot your chosen load? Target or hunting rifle? Semi or bolt?

I like to size as little as possible and with a few calibers and their dies I got lucky. Obviously with my AR's I like .002 - .003 and a boltgun somewhere around .002 or slightly less is a decent place to start (at least for me it is). I have about 10 different sized 21st Century expander mandrels (3ish per .224, 6mm, and 6.5mm) and settled on just one per caliber. Not a great way to waste my money but who knew.

Keep in mind that the smoothness of the ID of the neck (or layer of carbon even) can make a difference. Depending on what I'm loading, I've been known to chuck up a stiff nylon brush in my Casemaster Milwaukee (my drill clamped in my bench vice) and run my cases in and out. It makes a difference in seating feel compared to another case exactly the same but not run on the brush.

 

[SKWERLZ]

I thought I was going to try and set neck tension with different sized mandrels which I guess I still can I’ll just be limited because of no smaller than my die is sizing the necks.

Yep
If your mandrel is small enough to not expand the neck beyond its elastic range and into yield it’s not going to do anything to resize the neck.

I am actually playing with doing exactly that to see if just a slight ironing out with a mandrel slightly bigger than sized neck but so far the results haven’t been significant enough to notice anything

 

[markm87]

I hate pulling the expander ball back through the neck. Buy I don't shoot well either lol.

Decades back, I had no idea that the expander ball was adding so much runout and case stretch. I was clueless.

 

[DLT]

Yep
If your mandrel is small enough to not expand the neck beyond its elastic range and into yield it’s not going to do anything to resize the neck.

I am actually playing with doing exactly that to see if just a slight ironing out with a mandrel slightly bigger than sized neck but so far the results haven’t been significant enough to notice anything

I’m afraid that no more than my full length die is closing my neck down I’m going to see no use for the mandrels. I would have to either buy a different full length die and hope it closes it up or a bushing die. Original plan was to go the mandrel route to set my neck tension and not worry with bushings. As the die is now I can feel the expander coming through but it’s only opening it up .002 vs not using it.

 

[Dave M.]

I have a redding non bushing full length sizer. Using my adg brass annealing after every firing and using the expander ball, my necks come out consistently .270. Loaded rounds measure .271 I took the expander ball out and the necks came out of the die measuring .268 which gives .003 neck tension and that’s as small as I can go. I figure most run between between .001 and .003 tension. Most of my other full length dies will have .002 neck tension but it’s rough coming back through the neck with the exp ball meaning the die is closing the neck down way too much. I bought a mandrel die body from 21st century with the appropriate size and it came in .001 undersized what it’s marked so I can’t test any improvements using it

I have 5 separate rifles that all shoot best with 3.5-5.5 thou of “neck tension”. Don’t assume accuracy is only between 1-3 thou.
Dave

 

[Dave M.]

If you don't like the sizing die closing the neck down so much, you can always have it reamed to the specification you want??? Of course, that means you may have to have different size expander balls to get the neck tension you want.

Better yet, get a custom full length bushing die, no expander ball, and size like this, or go one step further and mandrel size after sizing down. Seems ridiculous to shoehorn yourself to strictly between 1-3 thou because that is the capability of the die you have. Time to buy a better die.
Dave

 

[Dave M.]

I think it’s closing enough. It’s not not closing near enough like my other dies have in the past. This one is barely working it which is a good thing Using the expander ball gets me .001. Not using it all all gets me .003. I have dies that without the expander ball it will ruin a bullet trying to seat

.003 neck tension with a tiny inside chamfer isn’t going to ruin or damage any bullet. I’m guessing you haven’t chamfered the inside of the neck if you are damaging bullets at .003” tension.
Dave

 

[DLT]

.003 neck tension with a tiny inside chamfer isn’t going to ruin or damage any bullet. I’m guessing you haven’t chamfered the inside of the neck if you are damaging bullets at .003” tension.
Dave

No not .003. If I typed that I did not mean it. And I told a lie about the die sizing down only .003 , when I took my measurement of just the die sizing without expander ball I had just taken off the bullet comparator and did not re-zero the calipers. They work great when used correctly. My necks measure .264 od without the expander ball, .269 with the mandrel and .270 with expander ball. Loaded rounds measure .271

 

[Dave M.]

No not .003. If I typed that I did not mean it. And I told a lie about the die sizing down only .003 , when I took my measurement of just the die sizing without expander ball I had just taken off the bullet comparator and did not re-zero the calipers. They work great when used correctly. My necks measure .264 od without the expander ball, .269 with the mandrel and .270 with expander ball. Loaded rounds measure .271

.007” neck tension is definitely on the extreme end, even for me. I’ve used 5.5 successfully in the past, but nothing more than that.
Dave

 

[Kracken McGraw]

https://www.amazon.com/Permatex-800...1925&sprefix=Permeated+valve+g,aps,152&sr=8-1
@AlNyhus posted this ^^^ the other day. I got some and just put some on a micro fiber towel and spun my expander ball just by hand in it. It polished it unbelievable smooth, and will take some material off too to get the size you want.