Testing Neck Tension

[onondaga]

There is probably no simple tool for testing neck tension, but I came up with a method to compare neck tension between full sized and collet die neck sized loads.

I am getting a neck collet sizing die for a caliber I have been FL sizing and this won't be my first collet die set. They are hard to adjust and get right so I will be testing with a kinetic bullet puller to evaluate neck tension on the bullet.

I am pretty well practiced with a kinetic bullet puller and have a swing consistent enough that it takes 4 medium swings to get a bullet out of the full sized round in this caliber. Swinging hard with a bullet puller is against the directions for the tool anyway and over the years I have developed a very consistent swing to get the job done.

I think a comparison bullet pulling between the two types of sized rounds will yield a relative answer to the adjustment setting of the new collet sizing die and how it affects neck tension relative to full length sizing in my caliber with the same bullets.

I would appreciate your comments.

Gary

[BABore]

Here's one I built based on 44Man's original idea and description. I pull on the small rod in front of the press handle to seat the boolits. The rubber witness washer records the peak force required to seat the boolit. The loaded rounds are segregated by lots for test firing. It sure cuts down on any vertical stringing in revolver loads. I used it to learn what to do and not to do when sizing and expanding cases.

[onondaga]

That is a serious contraption!!!!

Do you think I will be able to get a good die adjustment with my method?

Gary

[Blammer]

wow, you guys are serious about this neck tension thing.

I guess I'm just a back woods kinda guy.

I grasp my loaded round in my right hand and try to press the bullet into the case by pushing on the whole loaded round against the side of my reloading bench. If it don't go in, it's fine. If it do, it's not.

[Doc Highwall]

Gary, I am going to approach this in a different direction by making my expander's in different diameters. I just finished designing them for my 30-30 Win. and 308 Win. in .3090", .3095", .3100" and .3105". for bullet diameters of .3100", .3105" and .3110". This will allow me to increase bullet diameter and keep the same press fit of the bullet into the case. The one for my 308 Win worked out so great that I am anticipating great results with the sliding chamber and floating expander.

This is the thread that I started on it.
http://castboolits.gunloads.com/showthread.php?t=90241

The ones that I have designed this time will be made out of A2 steel and will be Titanium Nitride coated for lubricity.

[JeffinNZ]

DOC: Trouble is that neck tension is more than just a factor of the diameter you expand to. Hardness of the brass also comes into play. Do we all anneal consistently etc?

[Von Gruff]

I have my Wilson neck sizing dies and differently sized bushes. I have batches of brass with differing neck wall thickness and I use the apropriate bush to give me as close to a thou neck tension for cast and depending on ultimate use(ie plink or hunt) For J words I look for 2 thou and anneal regularly. High pressure loads at 4 load cycles and low pressure plinkers at 5-7 load cycles.

Von Gruff.

[Doc Highwall]

Jeff your are right about neck tension and annealing. What this will allow me to do is if I try a bullet that is .0005" larger in diameter I can also use a expander that is also .0005" larger so I only have one thing changed bullet diameter and not another .0005" press fit at the same time. Or I can try a .0005" smaller or .0005" larger diameter expander for bullet tension only. The gun will tell me what I want to know but not until I actually do it with only one varriable at a time which is my goal. If you read the thread that I started on this you will see that I am shooting some pretty good groups at 300 yards with my smallest measuring 1.600" for 5 shots with 4 of the shots just over 1".

[mpmarty]

Gary I would invest in a collet type bullet puller for this. I'd use a scale to pull the press handle something like a fishing scale and record the pounds of "pull" on the handle to extract the bullet from the case. Then with a formula derived from the length of the lever and the ratio of the linkage I could derive the actual pull necessary to remove the bullet from the case neck. As mentioned above the brass elasticity and neck thickness would enter into this also. I use a collet type neck sizer on 308 Win. regularly.

[303Guy]

So .... could one compensate for different brass strength and 'state of annealing' with different expander plugs or sizer dies based on such neck tension measurements?

[44man]

So .... could one compensate for different brass strength and 'state of annealing' with different expander plugs or sizer dies based on such neck tension measurements?
I have tried for years to sort brass BEFORE loading and it can't be done.
I would NEVER pull good loads apart to try and find the tension either. You are still fighting the brass in each case.
It has proven very easy to sort while loading. You make a different pile on the bench according to what the rubber washer stops at. Babore has taken my system a step farther with excellent machining. He is a craftsman for sure.
I have .44 BR dies special made for me with collars like Redding dies and a tool to measure case expansion after using the expander.
BUT THERE IS NO WAY TO SORT BRASS FIRST! [smilie=1:
The best dies are Hornady for more even tension.
I can tell you that loose fitting boolits will shoot down to 1/2" groups at 50 meters from a revolver and so will the tightest ones.
BUT, the groups can be 10" apart. Mix the loads and you are looking at 10" groups.
Tension is just not as important in a good rifle or semi auto pistol and crimp needs only to be enough to hold in boolits under recoil with a revolver. I really hate when someone says you need a tighter crimp! That is a sure way to ruin case tension or bulge brass.

[badbob454]

jeff your are right about neck tension and annealing. What this will allow me to do is if i try a bullet that is .0005" larger in diameter i can also use a expander that is also .0005" larger so i only have one thing changed bullet diameter and not another .0005" press fit at the same time. Or i can try a .0005" smaller or .0005" larger diameter expander for bullet tension only. The gun will tell me what i want to know but not until i actually do it with only one varriable at a time which is my goal. If you read the thread that i started on this you will see that i am shooting some pretty good groups at 300 yards with my smallest measuring 1.600" for 5 shots with 4 of the shots just over 1".

wow im happy with a 6"pattern at 300 yds my pulse moves the gun that much ....but, i love reading about the accuracy, some of you guys get ..i love accuracy but dont have the time to blast, and have accuracy so i concentrate on accuracy in my 223 only its probably down to 4" at 300 yds , but thats all me im a nervous old man , 57.. He he ... Keep on posting love the good read badbobgerman

[badbob454]

i have tried for years to sort brass before loading and it can't be done.
I would never pull good loads apart to try and find the tension either. You are still fighting the brass in each case.
It has proven very easy to sort while loading. You make a different pile on the bench according to what the rubber washer stops at. Babore has taken my system a step farther with excellent machining. He is a craftsman for sure.
I have .44 br dies special made for me with collars like redding dies and a tool to measure case expansion after using the expander.
But there is no way to sort brass first! [smilie=1:
The best dies are hornady for more even tension.
I can tell you that loose fitting boolits will shoot down to 1/2" groups at 50 meters from a revolver and so will the tightest ones.
But, the groups can be 10" apart. Mix the loads and you are looking at 10" groups.
Tension is just not as important in a good rifle or semi auto pistol and crimp needs only to be enough to hold in boolits under recoil with a revolver. I really hate when someone says you need a tighter crimp! That is a sure way to ruin case tension or bulge brass.

i dont understand this if you are sorting by case tension , why ignore case capacity wont different case sizes affect velocity ? And weigh each case foe consistency within each 'brand' ? Or do you do this too ?
Their are so many variables in reloading where does one stop ... My 2 c worth hope this helps not criticizing, just curious ... Also my 454 casull requires a hard crimp or the bullets will walk out and jamb the cylinder , dont want that hunting pigs or bear.. Happy shooting badbob

[fecmech]

If a fellow brazed an old socket to the pivot point on his press he could use a torque wrench to segregate his loaded rounds according to neck tension. That's essentially what BABore has done.

[BABore]

If a fellow brazed an old socket to the pivot point on his press he could use a torque wrench to segregate his loaded rounds according to neck tension. That's essentially what BABore has done.

I had thought of that as well. It had two drawbacks for me. I don't own one and you really need a recording torque wrench due to the where you would have to attach it. Thought it would be a real pain to have to bend down and try to read it for every boolit. I'm cheap and wanted the reading in plain sight.

Overall the whole process was a PITA. Useful and a good learning experience for sure. Most useful for wheelguns for me. Once you have a good feel for sizing and expanding to get the proper conditions, your all set.

Another method pointed out to me by 45 2.1 works well with both rifle and wheelguns. When you get a new lot of brass, do all your normal prep work and tweaks. Then load them with a known accurate load with good boolits. Shoot them all at the same target and throw out any case that shoots out of the group. Then the good case lot is always cycled through the reloading process as a group so they always have an equal # of firings. It takes alot of anal discipline to make it all work, but you reap what you sow.

[44man]

i dont understand this if you are sorting by case tension , why ignore case capacity wont different case sizes affect velocity ? And weigh each case foe consistency within each 'brand' ? Or do you do this too ?
Their are so many variables in reloading where does one stop ... My 2 c worth hope this helps not criticizing, just curious ... Also my 454 casull requires a hard crimp or the bullets will walk out and jamb the cylinder , dont want that hunting pigs or bear.. Happy shooting badbob
I do not mix cases but have found little difference in .44 brass. I do not weigh cases or boolits.
I have shot the .454 up to 55,000 psi with a moderate crimp without any boolit pull because I have case tension. We shoot the .44, .45, .475 Linebaugh, .500 JRH, .500 Linebaugh and the .50 Alaskan without more then a standard crimp. Only one boolit that is too heavy for the .50 Alaskan will pull crimp. It can't be stopped.
We have had more trouble with .454 factory loads pulling crimp then any other caliber. They were way over crimped and I asked Whitworth why they had so much crimp.
Boolit weight and recoil impulse is so very important. The .454 seems to have a very sharp recoil yet my loads do not pull.
If you look at factory jacketed loads for the .454 you will see a crimp so large and tight it actually harms the brass for reloads. I find it strange I can get boolits with lube on them to hold with less crimp at the same pressures.
What is really a laugh are those guys wanting to shoot 700 gr boolits from a revolver! :bigsmyl2:
It is a funny issue and I have no full answer but years of testing crimps has shown it has little bearing on powder burn and is only needed to hold boolits under recoil.
I have shot many rounds single shot from revolvers with no crimp with great accuracy yet too much crimp ruined accuracy.

[44man]

A recent test with a friends .454 Freedom We made. The left target were jacketed bullets with tight crimps. Shot at 50 yards. I did some work on the gun then shot these 5 shots with my cast boolit and they are PB to boot. Max loads of 296.
Yes, you can do it.

[Doc Highwall]

303Guy, the different size expander's are for cases with the same hardness and with case necks that have less then .001" neck wall thickness variance. Annealing will play a part of this and the quality control that I have while doing it. If you look in the Sinclair International Catalog for 6mm only they have neck bushings in .0005" steps to control bullet tension. The design flaw with neck bushings is any variation in neck wall thickness is moved it the inside causing bullet run out and a variation in bullet tension. Uniform neck turning will eliminate this but is time consuming and you really need a gun that is set up for this to eliminate over working the case necks. The LEE collet neck sizer advantage is because the case neck is pressed against a mandrel any variation in case neck wall thickness is now on the outside. The disadvantage is the mandrels are only one size from LEE with out being special ordered. This still leaves the problem with cast bullets in both of these dies that a lead is needed to start the bullet straight with out shaving lead. The floating expander's that I am making have a .3119" diameter to allow the bullet to start straight with the smaller diameter to control bullet tension in .3090", .3095".3100" and .3105" diameters. The carbide one I made is .3090" and works great with a .3100" bullet. What I am doing is I want to try both a .3105" and .3110" bullet and see if I can improve accuracy but I want to do it with only one variable at a time. If I use my .3090" with a .3105" bullet I will have two things that I changed at one time, a bullet that is .0005" larger and a .0005" greater bullet tension. So with what I am making I can go with a bullet that is .0005" larger and an expander that is .0005" larger and my only variable is the bullet not case neck tension. I will also be able to change bullet tension with the same size bullet by just changing the expander to a different size. Besides it gives me an excuse as to why I have a Bridgeport and a lathe to play with.

[onondaga]

Doc, I hadn't mentioned the caliber in my question. I have a new single shot Rem. Spartan in 7.62X39R. Full Length sizing decreases case volume too much for the powders I have chosen. The Lee Collet Die has been ordered with an additional .303 Brit. mandrel for a larger case neck I.D. for my cast sized .312" 151 gr FNGC boolits. I currently flair casemouth with the Lee Universal Expander die in a separate station on my turret press after FL size/prime.

The .303 Brit mandrel in the 7.62X39R collet die is supposed to give me the same size Neck I.D. as the larger of the 2 decap-expand pins supplied with my FL size die that I currently use. This larger pin is for .311-.312 bullets. Lee has advised me that the .303 Brit mandrel is good for .311-.312" bullets and I will have to cut it to length for the 7.62X39R collet die. I am hoping to get a couple more grains of powder into the Winchester cases I am using by neck sizing and not FL sizing. My accuracy is coming up but I have run out of powder room with 3 powders and no pressure signs in my load work-ups with this caliber.

I use Lee Collet Neck Sizing Dies in several other calibers and initial setup of these dies has been repeatedly difficult for me.. The collet dies are very sensitive to adjustment and press arm force closing the shell into the die for sizing must also be uniform. I try to get the die set for a firm lever pressure at the end of the stroke and also get the die adjusted for a good neck tension on the bullet. This has taken me a lot of trial and error with no other reference to neck tension other than pushing or pulling bulllets by hand after seating. .The Collet dies easily adjust from too loose neck tension to very tight neck in less than 1/4 turn with my other calibers.

My question still is, I wonder if using a kinetic bullet puller on a loaded round to evaluate neck tension is relative enough for a basic die setting on Lee Collet Neck Sizing Dies?

Gary

[HollowPoint]

I know it's already been stated but, You guys really are serious about neck tension.

If you're chasing the best accuracy possible I can fully understand your efforts. You've come up with some pretty good ideas.

Now days I'll do all I know to do to prep my cases, weigh my powders and seat my bullets as uniformly as possible.

Once I have all that locked down I'll go back after I've seated my bullets and (depending on the cartridge being loaded) apply a light crimp on each round.

I don't have any set formula for the amount of crimp I apply. I do it by feel. Not very scientific but it gives me uniform neck tension and seems to do the trick for me when I'm working up loads.

I also have a neck turning tool but with the store bought guns I load for, I don't know that it would do me any good to go that extra mile to turn all the necks.

If my rifles had custom match-chambers, then it might be worth my while.

HollowPoint

[Doc Highwall]

Gary, I think the only thing that you will prove trying to use a kinetic bullet puller is that it will be unrepeatable due to things like friction, surface finish on the I.D. of the cases along with how clean the I.D. of the case is. As far as adjusting the dies in our presses with a 7/8-14 thread pitch 1 divided by 14 = .0714" travel per one turn. To make it a little simpler lets round it to .072" per one turn, = .036" for 1/2 turn, .018" per 1/4 turn and .009" per 1/8 turn. I put this here for everybody to show them that in as little as 1/8 turn you are changing your dies head-space .009" with a full length sizer. This is why I use the Stony Point now Hornady head-space gage that attaches to a set of calipers. Gary in your case with the LEE collet die you can see that you have to turn the die in small increments, maybe you could attach a piece of masking tape on top of the press near the lock ring with a mark as reference to make a small adjustment. Gary did you look at the thread that I posted about modifying dies for cast bullets and how I use two locking rings jammed together, a LEE on the bottom and anybody's on top.
HollowPoint, most of the case neck tension is controlled by the size of the expander and crimp second and too much crimp can actually make the bullet loose in the neck just like we have all found some 22 rim-fire rounds.

[onondaga]

Thanks for the reference mark idea, I will do that.

I lock my dies down with a wrench on the lock ring when I get a final setting and I have used ink marks on the threaded area of the die and the top surface of the turret disk. So, after I finally do get them adjusted they stay locked on a turret disk for each caliber. The marked tape will help prevent wandering in the initial adjustments. Thanks.

Please provide a link to your post on modifying dies for cast bullets if not too much trouble.

Gary

[303Guy]

Thanks for the replies, 44Man and Doc Highwall. What you've both said has set me to thinking ....

BUT THERE IS NO WAY TO SORT BRASS FIRST! [smilie=1:
Well maybe there is - sort of. Because I know the size of my boolits, I can make up a set of sizer punches and dies to suite. It would be a bit of an effort but I could size the necks then use different expander plugs to 'measure' the expansion force (lubing and cleaning being a variable, I know) to minimize the spread. I do favour heavier boolits for among other things, the belief that they reduce the effect of neck tension differences. I also like to keep neck tension as low as feasable to minimise 'damage' to the projectiles which in my case my boolits are paper patched and to maximise the effect of boolit inertia upon firing. I have not done any scientific testing to demonstrate the value of my theory. (It did seem to work in my 22 hornet with heavier than usual j-words for the hornet and Lil'Gun powder with zero case neck tension. I got very good accuracy and performance while other folks using 'normal' loading techniques found it necessary to use crimping to get good accuracy with the same powder and lighter bullets).

[44man]

303guy, it just does not seem to be as important with a rifle because you have the rifling right there to offer resistance.
The revolver is the big bugger because of the room a boolit can move to the forcing cone. When tension varies too much, the primer pressure will move each boolit a different amount before full ignition.
Just making that movement as close to the same for each case will increase accuracy. It does not seem to matter if some are a little looser then others as long as they are not mixed.
I am not uptight about making brass real tight, just trying to make everything more even with the batch I am shooting. Firm tension is always better to resist primer pressure movement or heavy boolit pull from recoil.
That is the reason I found a standard primer works better in the .44 and .45 even with 296, reduced pressure from the primer itself.
Too much primer pressure can move a boolit out, force the powder away from the heat, delay or stop ignition. If tension varies too much you will have a different case capacity with each shot.
I have been able to make most revolvers shoot like a rifle at stupid ranges but I am sorry that I can't offer more knowledge with a rifle.
You have done some great work and if more even tension actually helps, please post your results.

[Doc Highwall]

Gary, another couple of ways to make small and positive die adjustments is company's like Redding makes shell holders that come in sets with different heights and are case head specific and the most expensive. The six set comes with a standard .125" height along with five more of +.002", +.004", +.006", +.008", and +.010" and Sinclair sells them for $44.95. Now for the good and cheaper news Sinclair International sells Skip's die shims for 7/8-14 dies in a 7 piece set .003" to .010" in .001" increments for $9.95. What you could do is set the die up initially with a .005" or .006" under the lock ring allowing you to either add or remove shims in .001" increments. With a couple of sets you could use these on all your dies as long as you write down what each die needs.

http://www.sinclairintl.com/.aspx/pid=33197/Product/Skip_s_die_shim_kit____7_8_14_

This is the link to Sinclair but you can try other places as well.

[onondaga]

Doc,

Skip's die shim kit looks like an inexpensive solution to the die adjustment problem for me to at least be able to make specific small increment adjustments. I want this set now and have added the link you provided to the "stuff I want to buy" tab in my favorites of my browser. The list is shamefully long---Thanks for adding to it!!!!!!

I feel the specific hassle of the sensitive Collet Die adjustment will disappear with this shim kit. .....Really good call from you. Thanks Again.

Gary