Neck tension

Deputy819 said:

Pay particular attention at the 54:20 mark where Jeff Siewert begins to explain the difference between "interference fit" and actual "neck tension".

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Thanks for the link to the Hornady podcast, it was very informative and I just found a good new podcast to add to my list.
Another thing they mentioned was having good results with using a slight crimp.
Why has that not been in this discussion much.
I have also seen where Butter Bean has been getting good results experimenting with crimps. At least with Hammer Bullets.

Flatbow said:

Thanks for the link to the Hornady podcast, it was very informative and I just found a good new podcast to add to my list.

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Welcome. It's a great podcast….and I especially like the ones with Jeff Siewert (Episode #110 Let's Talk Barrel Tuners, Episode #78 Let's Talk Barrels and Episode #54 Ammunition Demystified). Enjoy!

Thank you, I will start on those today once I get to work

It's sometimes nice having a job that most of the time I don't have to think to hard and can often times listen to podcasts

I run .002 for my loads that are magazine fed. I havn't had a bullet walk out from recoil yet with this tension.

When i single feed my 338 Lapua Magnum though, I go with .0015 neck tension.

These are things you can play with and go deep down the rabbit hole for sure. I have found that this has worked for me and I haven't changed things since.

2-3 is standard in a bolt action except in benchrest which is usually 1/2 to 1. 3-4 in semi-auto and tube feeds.

I generally develop a one bullet use in a rifle and that's what I stay with. It has to meet my wants. Which is grouping and velocity. The weigth of the bullet has to be in range for what type of animal I hunting. I set up and cut all my necks to a thickness. I anneal after the case has been fired, but before I size it. Grouping is done by several things. Neck tension is one of those items. It all goes hand in hand what works and doesn't work for your rifle. Likewise powders, primers, and neck tension crimping the necks. These are steps in reloading. Whether you incorporate one all the step is your discission.
Each rifle shoot a little different, and requires a little different set up. So that where the reloading come in at. It's up to you to determine what you want not what I want. This has been on neck tension. What people have found that works for them, and that may not work for you. I never really took into account neck tension until now. I'll have to seen what works, and doesn't work for me.
What I do see there isn't a real way to determine the tension other than how tight the neck is set at. Is it .001" or .002" of whatever. We can all measure our ID and OD of case and bullets. You can use bushing or mandreal to set those sizes in your neck. We can anneal everytime or whenever or not at all. To me it's part of the fun part on seeing what works and what doesn't work.
So that kind of gets me back from where I started at here. I generally only develop one load for a rifle. I stay with that going forward.

As with the last 30 years I'm still learning, but to me, IF you anneal each time, then there's no need for a bushing unless you're looking specifically for something other than .001 or .002" neck tension. I anneal, FL size with a regular non-bushing sizing die with the expander removed, then run a .002" turning mandrel to consistently set the ID neck tension. No neck turning, no OD bushing needed. Yes, I know I am working the neck more by sizing it down more than it needs during FL sizing, but since I anneal it doesn't really matter I don't think.

BTW, I had bought the 21st Century mandrel die body (with window) and a turning arbor for one caliber, but just bought the APW mandrel set from Pieter Malan at Impact Shooting Pro shop, which gives you a die body and TWELVE different arbors in six different calibers, .001" and .002" for each. Shipping was pretty steep from South Attica to California at $42, but compared to Sinclair or 21st Century the mandrels were a far better deal. I specified their reduced diameter mandrel die body for the Co-Ax.

Pieter has some serious $ tied up in reloading equipment, an AMP annealer, CPS primer seater from Primal Rights, and a Henderson trimmer, there's over $3k right there. (And you should check out his hunting videos, I think the guy is the luckiest hunter in the world based on his location and access to hunting gear). I'm lower tech and slower with an Ugly Annealer, hand priming with an original RCBS APS strip primer tool (although I have pre-ordered Carl's press mounted Precision CPS from Ugly Reloading, along with his set of improved Lee shell holders from Derraco Engineering, which is a beautiful piece of work with seating depth micrometer to .0005" adjustment) and an LE Wilson / Sinclair trimmer, but I appreciate the workmanship of the APW products.

Someday I may experiment with using a Redding S bushing die, or that die with a Short Action Custom bushing which I've heard good things about, before running the mandrels, but this gives me consistent neck tension and low TIR. Same with trying an LE Wilson inline seating die with arbor press, I'm just not there yet. I don't even have micrometer sizing or seating dies, but use Redding premium dies with their Accu-Ring lock ring, which gives me all the accurate adjustability I seem to need, but perhaps I'm missing something without that nice micrometer (?).

Anyway, I'm usually a lurker here and learn a lot from reading what the rest of you do, thanks!

Wow, almost $50 to ship it, that's crazy. I bought the shavings tray for my Henderson trimmer from him and that was a ripoff but he's the only one with something like that.

The way that I set neck tension is I first outside neck then my brass to the same thickness. This makes for consistent brass from piece to piece. Then I always Amp anneal before resizing. Then I take a bullet measurement and add the neck measurements and subtract .004". From there I use a bushing in my Redding type s fl resizer of that measurement. After that I set the neck tension with mandrel expanders from Porter Precision Products out of Texas, he makes some great tools at great prices and ships fast for cheap.

Currently I'm working on processing 1000pcs of brass for a 223 build I have in the works. It's time consuming but it only needs to be done once and the results have made the process well worth the effort.

tony, it is not if the bullets are going in the same hole, but what size is the hole? You never will know until you try, and there can be a tremendous difference in .0005 more or less, which is what the Wilson bushings can give you by just flipping them over, number size up gives stated dimension, number size down gives .0005 more tension.

It is amazing how many times I have seen groups go from high 2's to low 1's and zero's by a change in the bushng sizes. This is trial and error to find what the harmonics of the barrel likes. It only takes a few shots per size to access the trial as you are wanting the bullets to go into the same small hole. We have tuned factory rifles, bedded, bbls freefloated, triggers tuned, Great bullets, using great brass from Lapua, AGD, or Alpha , and great optics to shoot amazing groups at 600 yards.

A simple run out gauge to determine if your set up is giving you .002 and under run out is worth it's weight in gold....many systems can and will work. If you are getting .006 run out, you will be chasing your tail round and round on load development.

A simple wind flag placed 15' in front of your shooting position also teaches volumes for a start.

BrentM said:

Do any of you play with it or set it and tweak the loads? One of my rifles seems to really like .004-.005. Test load shown.View attachment 552727 It got me side tracked because I usually target .002ish and leave it for all rifles.

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My 6XC bushing die, that Tubbs sells, puts 5 thou neck tension. It shoots excellent. I generally order bushings to put 2 to 3 thou of tension. Neck tension would be the last thing I'd test, to get that last bit of accuracy. Imo, annealing every firing to ensure consistent neck tension is a must. Plus with proper "tight" headspacing and reasonably hot loads your brass will last 12+ firings, easily, even belted mags. Brass longevity is better with tighter tolerances. So I try to keep neck tension and shoulder bump to a minimum, ~2 thou for both.

Mikecr said:

When you guys talk about interference of 3-4thou, is that for FL of necks, or partial length sizing? For what cal?
Given the differences to tension I don't see how you can broadly declare anything without these qualifiers.
Then of course there is the alloy & worked hardness, which is mostly unknown, and then we can't even measure neck tension.

Seems like it could be said that we should experiment.
I don't know what phase of load development to include that in. Is it tuning or prerequisite to tuning?

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That a possibilities on length of sizing the neck. A great many years ago I switch to a neck sizing die for my 308NM rifle. I used a 300WM neck sizing die. It only sizes about 2/3" of the neck. It did two things. It stop my case separation at the base, and my grouping improved. At that time I only anneal once, but that stopped the neck cracking. I started cutting my necks for thickness too at the same time. So I really don't know what or which one had the most effect on grouping. I wish I had documented the changes and only did one change at a time. I'll be more careful this time going forward and more documention in changes made. Now that is changing greatly. Brass from same lot, All the pre-work on or in the case to start with. I still bullet seating depth, powders, primers, & seat depth for primers, My powder are petty much set with H powders. Primer I have most the different brand and types, just short 1 maybe 2 types. I know I am don't have Winchester LRM primer, and possible and I am not sure if Rem makes match primers. The sad thing is I'll probably end up using Fed-210 primers.
One new rifle and hopefully 2 additional rifles and a rifle that I'll be able to switch barrels to fireform my cases for 2 of them. So I'll be starting out like a brand new reloader almost, except I have been reloading 63yrs now.
This place is a big rabbit hole. and it's deep too. The thing I like the most about reloading is: I can change things if I won't like that I am getting. "Experimenting is the name of the game". Don't get mad, because somebody else does something different. It's not my way or the highway, but read and possible learn.

wasskeet said:

Brent, others - could you post what each component measurement is to arrive at a given neck tension?
Ex:
loaded round = X
bushing used = X
mandrel (if used) = X
etc.

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I encourage everyone to watch these and make your own decisions. Greg@Primal Rights.





PH