Neck Sizing W/ F/L Dies

[Pistol Ranch]

OK, here it is. I gave everyone a chance:

When a round fires in the chamber, the case expands every which way to seal. This case is now .005" to .010" larger than it used to be. A NS die will only size the neck because the body portion of the die is cut so oversize it does not even touch the body portion of the expanded case when the case is inserted therein. A FL, die, on the other hand, sizes the whole case, body and neck. What's gonna happen when you run a fired case into a FL die is the shoulder of the case will hit the inner sides of the FL die's chamber before the neck hits the corresponding neck part of the die. Being the FL die is designed to size the whole case, it will apply pressure to the edge of the shoulder and and cause an angular shift. Say the shoulder was 23 degrees, well now it is 20 degrees. Why is this important, well because when there is a change in the shoulder angle, headspace is also changed. In this case, because the angle was reduced, headspace decreased. Your case, if you were to remove it at this point, will not chamber in your rifle. So that's the folly of partial FL sizing. If you don't adjust the die to bump the shoulder at all, i.e. to neck size only, you will have a case that will not chamber.

Somebody made-up a term called "partial FL sizing". This involves sizing the whole case, but adjusting the die to bump the shoulder only enough to allow the bolt to close. This gives you about .001" to .003" of headspace and prolongs case life. This is what you use the FL die for, not neck sizing. Don't be cheap. Get yourself a Lee Collet neck die.

Depending on the round, some have longer necks than others and you may be able to size a small part tof the neck before the shoulder is touched by the die, but in most cases the shoulder will be sized before the neck even gets touched.

918: A simple question.. If it is necessary to F/L resize in order for a cartridge to fit a chamber, why do die manufacturing companys make NECK SIZING DIES ??
Since F/L dies ALSO resize case necks what's the purpose of having an extra die??
The uninformed need to know..

P.R.

 

[Innovative]

ranger335v .....

+1

Exact same thing. Full length resizing (when measuring die height) is the way to go, because there are no disadvantages.

The instructions that come with dies are very basic, and will work well enough for beginners. However, it seems to be only a matter of time before shooters want to make better handloads and shoot tighter groups.

 

[Innovative]

Pistol Ranch ......

There was a time ....... when neck sizing was the best way to go. However, time changes almost everything. Mass production tolerances are now much tighter than ever before. The vast majority of benchrest shooters today now use FL dies. No tactical shooter today would never consider using a NK die, because chamber failures are not an option. (Most SWAT teams are restricted to using factory loads only.)

Reloading equipment has come a long way. Just compare the car in your driveway to your grandfather's set of wheels. Change can be very good ....

 

[Pistol Ranch]

Larry: I am neither a benchrest nor tactical shooter. Neck sizing dies are still manufactured and being sold.
A statement was made that I MUST F/L resize cartridge cases or they will not chamber in my rifle. (If I read it correctly).
For the record..that is B.S.

P.R.

 

[918v]

You MUST bump the shoulder when using a FL die or the round won't chamber.

You can neck size when using a neck die. But after a few reloads, you will have to bump the shoulder.

 

[Innovative]

Pistol Ranch .....

Neck sizing dies are still being made and sold. However, they are not nearly as necessary as they once were.

The negatives of using a FL die set?

- If a FL die is set too low for your particular chamber, you will soon get headspace separations because of case stretching.

- If a FL die is set too high for your particular chamber, you will soon see rounds that don't fit in your chamber.

- However, if a FL die is set accurately, it makes your handloads fit with 100% reliably. (This requires measuring.)

 

[Walkalong]

Somebody made-up a term called "partial FL sizing". This involves sizing the whole case, but adjusting the die to bump the shoulder only enough to allow the bolt to close. This gives you about .001" to .003" of headspace and prolongs case life. This is what you use the FL die for, not neck sizing.

Exactly what I described many posts ago, but was chastised for it.

I'd like to coin a new term "Accurate Full Length Resizing".

I've been calling it partial full length sizing all this time. Because I measure where I am bumping the shoulder to, perhaps I should call it Accurate Partial Full Length Sizing.

I've been using "custom resizing" for some years with those I've taught to reload. "FL sizing" has a specific meaning by SAAMI specifications, that's clear enough. But, "partial FL sizing" is virtually meaningless in any real sense. My noobs grasp the difference between FL and custom resizing quite well.

Ok, Ok. Accurate Partial Custom Full Length Resizing.


On a more serious note, there seems to be some confusion still on using a FL sizer to neck size.

When adjusting a FL sizer to neck size, it will size the body to a degree. How much depends on the taper of the case. We have to size enough of the neck to hold the bullet so we will be sizing at least one half of the neck and probably closer to three quarters or more. When doing this the body is squeezed inwards and the shoulder starts moving forward which is the only place for it to go as the sides are squeezed in. Since we are not adjusting the sizer down all the way it is not contacting the shoulder so the shoulder stays forward from where it was when fired. This is where we can get into trouble with chambering. The shoulder can be too far forward to chamber.

We see this from time to time when a new reloader asks why their FL sized brass does not chamber. The answer is they did not have to sizer down far enough to get the shoulder back to where it was when it was fired, much less bump it back any.

 

[918v]

The shoulder can be too far forward to chamber.

Another way to say this is the shoulder migrates forward as the sides of the case get sized.

 

[JerryM]

I never found neck sizing with a FLRS die satisfactory. That is especially true with short necked cartridges such as the .243. If I sized the neck pretty much all the way the body also resized, but just enough to not chamber well.
Evidently others have found it OK, but I have always purchased a neck sizing die.
For me it has been money well spent.

Regards,
Jerry

 

[Walkalong]

Another way to say this is the shoulder migrates forward as the sides of the case get sized.

Yes. The sides being squeezed in push (migrate) the shoulder forward.

 

[JimKirk]

Walkalong... that makes at least two of us who have been describing the same process.



Call it what ever you want ... Partial Full Length Sizing... or

Finkley Fairy Farfully Fearful sizing or what ever some salesman wants to call it ...

You are in fact xx% partially sizing the brass so it most accurately fits your chamber.

It may be more knowledgeable to measure the fit ... but it does NOT have to be measured for "it" to work and be accurate as some tool salesman would have you to believe.

Jimmy K

 

[Walkalong]

it does NOT have to be measured for "it" to work and be accurate

I posted pretty much that many posts ago.

Many folks over the years have taken the firing pin and spring out of the bolt and sized the brass down a hair at a time until there was almost no resistance to the bolt closing. Works just fine.

We just don't have a number to go with it. I like gadgets and numbers, so I measure it.

 

[Innovative]

More than a salesman ....

JimKirk ......

I assume you're calling me the "salesman". In addition to being a salesman, I have over 40 years of solid reloading experience that helps a whole lot of shooters on a daily basis (for the last 10 years).

If you read my website, you'll find over 130 technical pages about great reloading tools that I don't make or sell, and I don't accept ANY paid advertisements. I've also spent over $250,000. manufacturing the reloading tools that I invented, patented, manufactured and distributed worldwide.

In this economy, it takes a fair amount of confidence for one person to make all this happen. That's not too shabby after being laid off like a jillion other fellow Americans. Over 4,700 shooters are now using my reloading tools.

All of the U.S. reloading companies do an outstanding job of providing customer service. However, I don't think any of them provide free tech support by phone and email like I do. (9 a.m. - 9 p.m. - six days a week), and I do this for ANY shooter whether they're a customer or not.

- I just thought you'd like to know .........

 

[918v]

If you don't know the exact size of your particular chamber (at the shoulder), how can you accurately resize your handloads? ... and ... if you don't measure your completed handloads, how can you know how well your resizing technique succeeded?

By feel. I can tell by how the bolt opens and how the bolt closes. The exact measurement does not marrer to me because each case is unique and springs back to a different degree. I set my headspace +.002" from where the bolt drags on the case. I use Redding competition shell holdes for that. Easy as pie.

 

[dsm]

The best of both worlds is to have a custom sizing die made to full length size your brass for your chamber.

 

[JimKirk]

You're right Larry... you are more than a salesman.

Thank you for all your contributions to the reloading community.

Jimmy K

 

[918v]

918: A simple question.. If it is necessary to F/L resize in order for a cartridge to fit a chamber, why do die manufacturing companys make NECK SIZING DIES ??
Since F/L dies ALSO resize case necks what's the purpose of having an extra die??

It is not necessary to FL size every time. You can neck size the same case several times before FL sizing becomes necessary.

The resason you have to eventually bump the shoulder through FL sizing is two fold:

1. Brass flows with each firing making the bolt harder to close. The higher the pressure, the more the brass flows.

2. The total amount of square footage inside the chamber is contained by the bolt face. The bolt face is seldom square with the chamber. When the round fires, the case fills the chamber and conforms to the bolt face as well. If the bolt face is not square, one side of the casehead will flow more than the other. Now, when you remove the case, rotate it 180 degrees, and reinsert it into the chamber the longer side of the case will be sitting in the shortest part of the chamber. This will make closing the bolt difficult.

Reasons 1 + 2 are why we bump the shoulder.

Now, you can make a custom rifle having everything perfectly square with a custom chamber having a 40 degree shoulder and shoot moderate loads through it. You will never have to FL size that case. Neck sizing will suffice. But most rifles are not square. Bolt face runout runs as much as .005" and only one bolt lug makes contact with the receiver most of the time. We FL size for such rifles.

 

[MCMXI]

^^^^

Excellent post there and precisely the reason why I no longer neck size only. I use Redding neck sizing dies followed by Redding body dies to bump the shoulder back every time. I try to bump the shoulder back 0.002" ~ 0.003" from the maximum fired case dimension. After measuring 400 cases that have been fired four times each (1,600 reloads), I find that this method yeilds the best results ... for me.

 

[JimKirk]

Funny thing..I just found an article by the reloading guru in "Shooting Times" magazine (March 2009).
His procedure for setting F/L dies is as follows..
1.Raise ram and screw resizing die in until it touches the shellholder.
2.Lower ram and back off the die 1/2 turn and lock.
3.Size one case.
4.Try the case in your rifle, if it chambers easily you may have headspace
issues..time for a gunsmith check.. (Note: No gage necessary to see if the case will chamber..its a simple yes or no..)
5.If case will not chamber, turn die in 1/8 turn and try again with a new case.
6.Repeat step 5 as necessary ( 1/8 turn at a time) using a new case each time until a case chambers with a slightly snug fit.
7.Lock die permanently.
8.Resize all cases used above.
The stated advantage of the above is that you will have a die set correctly for your rifle..Using the old method of screwing the die in 1/4 turn after lowering the ram can result in excessive shoulder set back..

Sounds like a plan !!

This ^^^ is what some of us have been saying to you the whole time... been working for me for almost 46 years now. Partial Full Length Sizing!

Jimmy K

Not sure how this post made after 8am showed up ahead of the post I Quoted at 2:28am ..when I was sound asleep at that time.....

 

[Walkalong]

This has gone in circles so many times I'm getting dizzy.

 

[Walkalong]

I see what you mean JimKirk. I just posted at 8:33 AM, and it showed up as 2:34 AM. I posted after PR, but it showed up before his.

 

[Pistol Ranch]

Funny thing..I just found an article by the reloading guru in "Shooting Times" magazine (March 2009).
His procedure for setting F/L dies is as follows..
1.Raise ram and screw resizing die in until it touches the shellholder.
2.Lower ram and back off the die 1/2 turn and lock.
3.Size one case.
4.Try the case in your rifle, if it chambers easily you may have headspace
issues..time for a gunsmith check.. (Note: No gage necessary to see if the case will chamber..its a simple yes or no..)
5.If case will not chamber, turn die in 1/8 turn and try again with a new case.
6.Repeat step 5 as necessary ( 1/8 turn at a time) using a new case each time until a case chambers with a slightly snug fit.
7.Lock die permanently.
8.Resize all cases used above.
The stated advantage of the above is that you will have a die set correctly for your rifle..Using the old method of screwing the die in 1/4 turn after lowering the ram can result in excessive shoulder set back..

Sounds like a plan !!

P.R.

 

[Walkalong]

Check, check.....Yep, Time Warp fixed it seems.

 

[Pistol Ranch]

We are obviously in the twilight zone..I get quoted Before I post.

P.R.

 

[918v]

Ask JimKirk for next week's winning lottery numbers.