Extreme neck tension problems

[wchartz]

I have been reloading rifle rounds for about 50 years but have never encountered this problem to this magnitude. I am reloading .260 Remington using Redding type S match dies. I started with new Laupa brass and Sierra 142 and 123 MKs. The brass necks were lubricated with Imperial dry lube and run through the neck sizer with a carbide expander ball. The neck ID was then gererously chamfered. The neck ID measures .262. As I was seating bullets I noticed that it was taking an unusually high force to seat the bullets, something on the order of 20-30 lbs. force on the handle of my Rock Chucker. The powder charge is not compressed. When I checked the lenght to ogive using a Sinclair comparater I see variations in lenght of about .022". After investigating several possibilities. I notice that there is a crimp of varying depth around the circumference of the bullet about .250" from the tip. This is an imprint of the seater plug. There is a direct correlation between the crimp from the plug and the lenght of the round. The deeper the crimp the longer the round.
Obviously the more force used to seat the bullet the deeper the crimp and therefore the longer the round. It gets more interesting. I also have some new Winchester 7mm-08 brass that I necked to .260 using the same technique. These also took an unusual amount of force to seat. I did only five of these. The lenghts on the comparator for these were; 3.227, 3.216, 3.200, 3.209, 3,228. I pulled these bullets using a Forster collet puller. It was all I could do to tighten the collet enought to remove the bullets and then I would have to try three to five times on each round. I could not remove one bullet at all using the puller even after hammering the puller handle as tight as I dared try. I finally raised the round through the empty die hole in the press and clamped a pair of vise grips on the bullet and lowered the round and thereby pulling the bullet. It must have taken about 40 lbs. of force to remove the bullet.
Could there be another problem besides brass necks being too hard? Having two different brands of new brass do the same thing is very strange. The neck thickness of both brands of brass runs from .0145"- .015" on a fairly consistent basis.

 

[Skum]

Re: Extreme neck tension problems

im not an expert by any means on rifle reloading but on my 1st read, bushing size and correct size expander ball came to mind..

im guessing your using a .288 bushing

 

[RTH1800]

Re: Extreme neck tension problems

Sir,
I am not sure I fully understand why COAL or seating depth have to do with seating pressure.
I will address what I do understand.
First, I would remove the expander ball. Secondly, I would measure the OD of a loaded round. Let's say it is .290, then get a .288 bushing. Size without expander ball, just use the button to retain the primer punch pin. With your expirence, I think you already know all this. With .002 neck tension, you should not have seating issues. When I find a case that otherwise meets spec for the lot but does not feel the same seating the bullet, I pull it out and do not shoot it at LR. Hardness could be a factor, but I really do not think so in two lots of two brands of brass. JMO

 

[Skum]

Re: Extreme neck tension problems

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rth1800</div><div class="ubbcode-body">Sir,
I am not sure I fully understand why COAL or seating depth have to do with seating pressure.
I will address what I do understand.
First, I would remove the expander ball. Secondly, I would measure the OD of a loaded round. Let's say it is .290, then get a .288 bushing. Size without expander ball, just use the button to retain the primer punch pin. With your expirence, I think you already know all this. With .002 neck tension, you should not have seating issues. When I find a case that otherwise meets spec for the lot but does not feel the same seating the bullet, I pull it out and do not shoot it at LR. Hardness could be a factor, but I really do not think so in two lots of two brands of brass. JMO </div></div>

thats what i was trying to get at but i didnt want to give false information just a general direction.. hope he works out his issue

 

[gcoulsey]

Re: Extreme neck tension problems

What bullet seater die are you using?
Is it a crimping type seater improperly adjusted for the bullets?
i.e. it's trying to crimp the case mouth while still seating the bullet?

Usually this produces buckled or bulged cases, but if it's right on the edge of the crimping operation it could be applying just enough resistance that you are encountering, hard seating and bullet deformation/irregular seating depth without the case deformation?

 

[Deadshot2]

Re: Extreme neck tension problems

Try annealing a couple of cases and see if the seating pressure changes after resizing. The brass can have more springback than you're used to. Also, mic the expander ball in the die.

I now use a Sinclair Expander die on all my rifle brass just prior to seating bullets. Has definitely made a difference in uniformity of seating pressures and a resultant consistency in neck tension. The results of this extra step has shown up on the target as well.

I'm loading .308 but the principle still remains. One last expansion of the case neck with a mandrel rather than a ball yields straighter and more uniform case necks.

 

[MALLARD]

Re: Extreme neck tension problems

where is this crimp coming from ?

 

[ejb]

Re: Extreme neck tension problems

i'm with gfunkUK improper die adjustment if it's a crimp die try backing it out a little and reajust seating stem.

 

[wchartz]

Re: Extreme neck tension problems

I appreciate the responses but it is evident that several of you do not know what Redding type S Match die sets are. The seater is a chamber type die with a floating bullet seater. It does not have the ability to crimp. The sizing die is a neck only and has interchangable bushings to vary the amount of neck sizing. For this operation I was using an oversize bushing with the carbide expander ball. Remember that is new brass and already sized. I am just straightning out the slight neck irregularities.
I called Redding technical support this morning and was informed that everything was normal as I explained it. The Tech said that I needed a Special VLD seater plug. This plug more closely fits the profile of the bullet nose and should not put a crimp in the bullet. If that is the case the lenghts should be uniform. I ordered the seater plugs from Sinclair. I will report back my results on this thread in about a week. I agree that annealing the necks would help this problem but I should not have to anneal new brass. Thanks all.

 

[Tunanut]

Re: Extreme neck tension problems

My shoulders collapse when there's too much neck tension, another benifit of AI. hehe Try the expanding mandrels from Sinclair instead of balls, you may like them better. Going up a bushing size or two may also help if you have that much neck tension. Whenever I change the size of a neck, I do it several bushings or expanding mandrels (5 thou or so at a time) and anneal between them. It really helps them stay where you sized them without the springback.

 

[steve123]

Re: Extreme neck tension problems

It could be possible that the seater die has a smallish diameter in the neck area than the measurement of a loaded round. So when you seat a bullet, the bullet expands the brass to a larger diameter than the neck portion of the die will allow, thus causing the excessive seating force you are feeling and also deforming the bullet ogive.

I've had the phenomenon you are describing happen on a custom seater die before. The die had worked fine until I changed bullets. I solved the problem by neck turning .001 off of the necks.

 

[groovinpickle]

Re: Extreme neck tension problems

I bought a VLD stem for my caliber (.223 Rem) and my results were not great. After maybe 1500 rounds the die was binding, and producing ammo with poor consistency. I took it apart, which required the aid of tools to remove the stem from the sleeve. The standard stem dropped right in. I mic'ed the OD of both stems and found that the VLD stem had belled out about a thousandth of an inch, which was causing this binding.

I did a little research and apparently this is old knowledge among high-volume shooters running a compressed load and VLD bullets. It seems that the VLD stem is a little more fragile. Lots of folks have reported them cracking, although I can't say that mine did. You may not have this problem if you don't seat on compressed loads a lot, and if you use a gentle touch when seating. Instead of ordering a replacement stem I ordered a Forster seating die and have been very pleased with it so far.

Just my two cents.

 

[Rthur]

Re: Extreme neck tension problems

What size bushing are you using in the neck die? What is the neck thickness on the 7-08 brass? How many loadings have these brass had? Have you checked for a donut in the neck at the shoulder?(this isn't uncommon with necked down brass)

R

 

[Paladin2147]

Re: Extreme neck tension problems

Unless you neck turn, you can only "control" the id. with some sort of expander. Bullets make poor expanders. Also see...

http://en.wikipedia.org/wiki/Galling

 

[wchartz]

Re: Extreme neck tension problems

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rthur</div><div class="ubbcode-body">What size bushing are you using in the neck die? What is the neck thickness on the 7-08 brass? How many loadings have these brass had? Have you checked for a donut in the neck at the shoulder?(this isn't uncommon with necked down brass)

R </div></div>The Laupa brass was sized only by the expander ball since I used an oversize bushing. I just wanted to remove the minor dents in the neck. The Winchester brass was sized using a Redding standard FL die with carbide expander. The donut if there is one is only .002" larger in diameter at the base of the neck. This is on the o.d. and would not affect neck tension unless there was interference when chambered. All of your other questions were answered in my original post.