Reloading Nembie question. Neck tension.

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logan1080

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I have read both Hornady's reloading book and Lynmanns reloading guide and I am still not clear on how to adjust neck tension. How do you change the case neck diameter to adjust neck tension? Are there dies that are adjustable? How much neck tension is generally used a magazine fed bolt action rifle? couple thou?

Also, what is prefered as far as dies go? I just want neck sizing dies so I can benefit from fire formed cases but I see RCBS has 2 die sets or 3 die sets. What is the advatange of having a 2 die set vs their 3 die set?

Thanks for helping another reloading newb!
 
Good for you for reading a couple of manuals first!

The 3 die RCBS rifle sets come with FL, neck and seating dies. 2 die sets just have FL and seater.

Take a look at the Redding site for information on their bushing dies. This will help with some of your questions relating to neck tension and how to control it more precisely. The Redding dies are great if you should decide to go this way.

Unless you're looking for extreme accuracy from a gun which is up to the task, you'll be fine with either 2 or 3 die sets from RCBS to get you started.

There have been lots of posts here on the subject also - try searching right here on CGN.

Good luck! SD
 
Neck tension can be adjusted by varying the diameter of the expander ball in a conventional die, or Redding makes a die with different diameter bushings that squeeze the neck to different diameters as need to get the neck tension desired.

There is a DVD on the market by John Barsness - "Accurate Reloading, Beyond the Basics" the shows the difference between the two die types. It also talks about desired neck tension etc. I really like it and watch it at least once a year.

As for desired neck tension, I believe the rule is two thou for bolt actions.

As for the RCBS 3 die sets, in addition to the full length sizing dies, it comes with what is called a neck sizing die that only sizes the neck of the case, leaving the body untouched so it should then conform to your chamber size. The jury is out on whether on not this is the best way. Some rifles show improved accuracy, some do not. A FL sizer dies shrinks the whole body of the case. If you fire and neck size a case enough times though you will have to FL size it eventually as it will expand to the point that you can't easily chamber it.

RCBS dies all use expander balls which I personally have found contribute to case stretching. The neck is compressed under size by the die and then opened up as the expander die is drawn back up through the neck. This also natually pulls the brass in the neck, though this can be mitigated by lubing the inside of the neck with a dry lubricant.

I prefer the collet die from Lee for neck sizing as it simply squeezes the neck against a mandrel which does not stretch the case IMO.
 
Was looking at the reddings with different bushings. This seems like a decent option also? I will be reloading for maximum precision as I have a rifle designed to do so and that is the main reason I am going to be loading.
 
I've said it many times. Reading multiple reloading books, of the huge, modern type, opens the door for confusion.
The OP is worked up about a "problem," that may not appear in a lifetime of reloading. Based on my near lifetime of reloading, I have never come across a problem with neck tension on the bullet. I have reloaded for many different calibres in rifles and handguns, using virtually every brand of brass case out there, all the different bullets I fancied, using standard, good quality dies and never had a single problem with neck tension, or lack of.
I never had to change the neck resizing plug, to change tension, ever.
 
You can fine tune rather easily with a Lee Collet die by adjusting die depth until you get the tension you want. I have found that runout is also very low. Some poo poo these lower cost dies....but they just work. My two bits....
 
Not to over-simplify, but consistency is probably more important than the amount of tension for accuracy. So, having necks with the same wall-thickness run through the same die should basically give you what you need. Neck-turning will achieve this, if needed, as well as help with bullet concentricity.
 
neck turning, bullet concentricity is all being cosidered when putting together a bullet. I was just curious on how neck tension is adjusted.
 
Dmay said:
Not to over-simplify, but consistency is probably more important than the amount of tension for accuracy. So, having necks with the same wall-thickness run through the same die should basically give you what you need. Neck-turning will achieve this, if needed, as well as help with bullet concentricity.
Click to expand...

I think you mean the run out of loaded rounds? If not please explain, thanks.
 
yep.....concentricity = run-out.

Its just that when I finally learn a big word, I wanna get all the mileage I can out of it.......
 
As mentioned above, neck tension is "adjusted" either through use of varying outside diameter expander plugs - most available by custom order,- or by neck sizing bushings, again of varying ID.

For benchrest accuracy, I understand the big boys aim for absolute minimal neck tension. This can only be successful in absolutely uniform case neck thickness, no matter how you size them - hence neck turning - and absolutely consistent bullet diameter. Match cases and match bullets only need apply.

Prolly a query on one of the benchrest boards would get the hotest gen, from the current winners.
 
I use the Redding bushing dies to adjust my neck tension. I also find that my case life increases significantly, because the brass is worked much less.
 
I agree , a collet neck sizing die is the way to go, also the neck turning isn't a terrible idea.When you just shave a little off the neck you can see the inconsistency in the neck thickness.

Is it neccessary , not at all for hunting rounds, target and match ammo sure,but I like to do it just to see what is happening with my brass. Also when sizing brass from a different sized casing it is nice to get everything iniform.

Just my $0.02.
 
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