Neck Tension

[BeefyT11]

Do you test different amounts if neck tension? Or do you have an arbitrary amount you use across the board? At what phase in the reloading process do you test?

I'd appreciate it if you could state your discipline if you do state an amount of neck tension in your answer

Any info is good info, thank you

 

[PopCharlie]

I shoot .0007 to .001 neck tension for both my .223 and 6.5x47L. I F/L size using a non bushing sizer with a polished ball that is .0015 under the bullet diameter. I seat using a K&M arbor press with the force pack installed. Seating force runs 15 to 20 lbs. I experimented with alot of different sized expander balls before arriving at this. I get the lowest ES and most consistent accuracy. I shoot a 6.5x47 Lapua and a .223. The 6.5 runs a little less seating force, 12 to 16 lbs.

PopCharlie

 

[Howland]

I did an OCW for .338LM from start to max charge per Hornady X. The best accuracy was toward the lower end but velocity ES was horrible, 200 fps+!

I picked up a set of mandrels thinking that I wasn't getting consistent ignition and more bullet tension might resolve the issue. I tried 0.002 through 0.004 interference fit in 0.0005 increments. It did not resolve the unacceptable ES, but the testing did establish that my rifle is more accurate with 0.003 interference fit.

I then repeated my load development. Optimum seating depth didn't change. The charge weight of the smallest group didn't change despite the same very poor ES, still near the start charge. Testing was done at 200yds. My final decision was a compromise between velocity, ES, group size and point of impact. To date my best group was shot at 400 yards, the limit of my home range. I have much more confidence that performance will hold up at further distances.

 

[JimSC]

Bryan Litz did a test in his Modern Advancements vol II book. He found that that .003 was optimal for his .223, .243, and .308 rifles. That is what I have been running ever since I read that book. Works pretty well for me in F class shooting with 6BR and .260 rem

 

[skeeljc]

I shoot .0007 to .001 neck tension for both my .223 and 6.5x47L. I F/L size using a non bushing sizer with a polished ball that is .0015 under the bullet diameter. I seat using a K&M arbor press with the force pack installed. Seating force runs 15 to 20 lbs. I experimented with alot of different sized expander balls before arriving at this. I get the lowest ES and most consistent accuracy. I shoot a 6.5x47 Lapua and a .223. The 6.5 runs a little less seating force, 12 to 16 lbs.

PopCharlie

Please tell me more about your "non bushing sizer" and "polished ball" expander.

 

[PopCharlie]

Please tell me more about your "non bushing sizer" and "polished ball" expander.

I use a Forster benchrest non bushing full length sizing die. It has interchangeable expander balls. I polish them using a Dremel tool with a polishing wheel on it to make them smooth. The ball slides back thru the neck more easily. As a result, inside diameter of the neck is very consistent.

PopCharlie

 

[K22]

I use traditional full length sizing dies with standard expander ball assemblies. I have several expander ball assembles per caliber that have been polished to produce different sizes in .001" increments. (2 to 4 assemblies per caliber cover my needs for most rifles) For me this is the cheapest, simplest and easiest way to have some control over neck uniformity.

Typically I'm getting about .002 to .006" of neck tension depending on the caliber and the rifle. I really don't care about the amount within reason as long as it's consist for that rifle. What I'm hoping to achieve is uniform expansion of the neck. What I don't want is excessive drag on the case neck that increases the chance of distorting the neck.

I want to keep things as simple and uncomplicated as possible. I don't want to turn necks or use bushings. For me it's not necessary to achieve my goals. My "discipline" is precision varmint hunting. As long as I can place consistent shots in the vitals of a ground hog or coyote at the distances that I hunt I'm satisfied.

With my precision rifles, my tailored reloads will hold consistent five shot groups within 1/2 moa if I do my part. I'm not a good bench shooter and don't spend any more time on the bench than necessary and only for initial scope sight in or load development for a new rifle. I do almost all my range shooting off shooting sticks to simulate field shooting conditions.

 

[skeeljc]

I use a Forster benchrest non bushing full length sizing die. It has interchangeable expander balls. I polish them using a Dremel tool with a polishing wheel on it to make them smooth. The ball slides back thru the neck more easily. As a result, inside diameter of the neck is very consistent.

PopCharlie

I have been trying to find a Forster Bench Rest FL die so I can get Forster to open the neck some. The FL die reduces the neck more than I want. Right now Forster is out of dies and so are all of their distributors.

 

[BeefyT11]

I use traditional full length sizing dies with standard expander ball assemblies. I have several expander ball assembles per caliber that have been polished to produce different sizes in .001" increments. (2 to 4 assemblies per caliber cover my needs for most rifles) For me this is the cheapest, simplest and easiest way to have some control over neck uniformity.

Typically I'm getting about .002 to .006" of neck tension depending on the caliber and the rifle. I really don't care about the amount within reason as long as it's consist for that rifle. What I'm hoping to achieve is uniform expansion of the neck. What I don't want is excessive drag on the case neck that increases the chance of distorting the neck.

I want to keep things as simple and uncomplicated as possible. I don't want to turn necks or use bushings. For me it's not necessary to achieve my goals. My "discipline" is precision varmint hunting. As long as I can place consistent shots in the vitals of a ground hog or coyote at the distances that I hunt I'm satisfied.

With my precision rifles, my tailored reloads will hold consistent five shot groups within 1/2 moa if I do my part. I'm not a good bench shooter and don't spend any more time on the bench than necessary and only for initial scope sight in or load development for a new rifle. I do almost all my range shooting off shooting sticks to simulate field shooting conditions.

How do you determine where between .002 and .006 you stick with? Do you test different amounts during load workup?

 

[PopCharlie]

I have been trying to find a Forster Bench Rest FL die so I can get Forster to open the neck some. The FL die reduces the neck more than I want. Right now Forster is out of dies and so are all of their distributors.

I anneal after each firing, so I don't worry about over working the brass. My .223 die sizes to .220 without the expander ball installed. I use a .223 expander ball.
I've read on this forum about shooters using honed Forster sizing dies. I'm going to try that with my new 6br when the build is done.

PopCharlie

 

[BoydAllen]

Years back, one day when I was loading at the range for my 6PPC with 133 I did a little test. With a load that was tuned with .003 neck tension, which I starting using after it was suggested by a very good shooter, for that powder. I tried .001, .002, and .003. Looking back, I should have done a minor tune up with each, or at least with the first two, since I was already in tune with .003. Every time I try a different powder, I do a neck tension test. I have fond powders that like quite a bit, and others that do not. If you have a question that you have the means to test, I suggest that you do.

 

[BeefyT11]

Years back, one day when I was loading at the range for my 6PPC with 133 I did a little test. With a load that was tuned with .003 neck tension, which I starting using after it was suggested by a very good shooter, for that powder. I tried .001, .002, and .003. Looking back, I should have done a minor tune up with each, or at least with the first two, since I was already in tune with .003. Every time I try a different powder, I do a neck tension test. I have fond powders that like quite a bit, and others that do not. If you have a question that you have the means to test, I suggest that you do.

Thank you for the input. At what stage do you test now? What are indicators that one shines above the rest, if you are already tuning with a certain amount of neck tension? Es? Group size?

 

[BoydAllen]

I would trust your targets, shot at the distance you will be competing at. What I have found is that some of us are a lot more curious than others, and that while we enjoy experimenting, not all do. One of the reasons that I like to load at the range is that I don't have to wait for my next trip to the range to test something that I thought of based on my most recent results. Often, I only need a couple of shots to see whether a load has promise. If the first two shots look ugly, adding more will not fix that, and if the first two look good, then I have reason to continue. Of course you have to have a lot of confidence in your equipment and ability to do it that way.

 

[Howland]

Years back, one day when I was loading at the range for my 6PPC with 133 I did a little test. With a load that was tuned with .003 neck tension, which I starting using after it was suggested by a very good shooter, for that powder. I tried .001, .002, and .003. Looking back, I should have done a minor tune up with each, or at least with the first two, since I was already in tune with .003. Every time I try a different powder, I do a neck tension test. I have fond powders that like quite a bit, and others that do not. If you have a question that you have the means to test, I suggest that you do.

Did you find any generalities, such as faster powders working better with less interference fit and slower powders with more, or the opposite? Or have you concluded there is no or low correspondence?

 

[BoydAllen]

Did you find any generalities, such as faster powders working better with less interference fit and slower powders with more, or the opposite? Or have you concluded there is no or low correspondence?

All of my testing has been done with powders that are of a suitable burn rate for a 6PPC, with bullets typical for that caliber for short range competition.

 

[skeeljc]

I anneal after each firing, so I don't worry about over working the brass. My .223 die sizes to .220 without the expander ball installed. I use a .223 expander ball.
I've read on this forum about shooters using honed Forster sizing dies. I'm going to try that with my new 6br when the build is done.

PopCharlie

I have had a .223 Forster BR FL die on order with Forster since early December. I have a Redding FL die. Maybe I will try to hone it out. My Redding FL die sizes the neck to .240" OD.

 

[BeefyT11]

Thank you everyone

 

[K22]

How do you determine where between .002 and .006 you stick with? Do you test different amounts during load workup?

I start with an expander ball that's .003" under the diameter of the bullet. For example, in a 223 Rem (.224 bullet diameter) I start with an expander ball that's .221. If this creates too much drag on the neck or not enough expansion then I go up or down depending the lot / brand of cases. Each 223 Rem rifle has it's own set of dedicated, same lot cases. I have some sets of cases that require a .219, other sets that require a .220 and others a .222 but .221 works for most. Once selected for a given set of cases, most of the time the expander ball size remains constant even up to 15 reloads.

I should also note that I'm loading for 10 different 223 Rem bolt rifles and using Remington, Winchester, and Hornady cases which have varying neck wall thickness. As stated earlier - each rifle has it's own dedicated same brand, same lot of cases and the cases are uniformly rotated so they receive the same number of firings and sizing.

What I'm trying to achieve is a relatively uniform expansion rather than a precise neck tension number. It's no where near as precise as turning necks, using bushing dies, and annealing but it works close enough for my purposes.

I also polish the expander ball with 220 grit paper to produce a mirror like finish which reduces drag on the neck. In addition, I've found that if I use a nylon neck brush (no lube) to clean out the neck of excess carbon this aids in reducing drag of the neck. I chuck the brush with a drill adapter into a low RMP drill and brush out the necks which speeds up the process and does a better job and doing it by hand. My expander balls do not exhibit any carbon residue after sizing.

No, I don't test in load development. In my experience as long as the neck expansion is relatively uniform it hasn't affect the precision of my reloads but I'm only loading for varmint hunting seeking reloads in the 1/2 moa + or - range.

 

[skiutah02]

I shoot primarily FTR (FClass). By accident, I discovered how critical neck tension is to accuracy pretty early in my reloading career. After powder, presuming you are in the right powder node, consistent neck tension is probably the second most important variable in accuracy to my findings. This assumes quite a bit of stuff like you are committed to a particular caliber, bullet, chamber, brass, etc, however. And can be barrel dependent.

For my 223 and 308 they have been pretty sensitive to NT. For my 6BRX, 6.5x47, 6.5CM and a few other variants, not so much - not gains in accuracy from changing NT.

I start my testing with 0.002 tension and retest it from 0.001 to 0.006+ after settling on powder, seating and primer, but I test the NT at distance 300+, usually 600 or 1000 yds. So very late in the process for me and right before I test my tuner effects (tuner is off of the barrel before testing it).

I have found that very high neck tension is the most accurate for my 308 (across 10+ barrels). I run 0.004 to 0.007 in many barrels. This cuts against common wisdom, but the targets do not lie.

Here's a recent test shot last month. The odd numbered shots are with 0.007 NT and the evens are 0.005 NT. Shot at about 970yds. Drew

 

[skeeljc]

I am not sure you can have anything more than ,003" neck tension. At some point you will yield the case neck when you seat the bullet. The way to find out is to pull a seated bullet and measure the neck OD and compare it to the loaded neck OD.