Better to have FL die or Neck and Body die separate?

[mardanlin]

Is there any difference in case life expectancy when using a FL die as opposed to neck-sizing only for the first firing and then body-sizing when they get hard to chamber? It seems like the brass would need less reshaping that way and would extend the case life, but I'm not sure if that's how it actually works.

If it turns out that I'd rather size the body every time along with the neck, would I be better off having the FL die or the other two separate? A FL die would probably be faster because one die does both things but other than that, is there any real difference?

[Reloader2]

It seems I've read somewhere that neck sizing will extend case life because the case doesn't stretch as much with each firing. I've been reloading since 1994 and I use both methods of sizing. So far the only failures I've had have all involved the neck of the case.

[Clark]

I hand load; 19 Badger, .222 .223, 22-250 6mmBR, .243, 25acp, 25/20 25/35, 250/3000, 257 Roberts AI, 260, 6.5x55, 6.5-06, 270, 7x57mm, 7mm Rem mag, 32acp, 32sw, 32S&WLong, 32-20, 7.62x25mm, 30 Mauser, 30-30, 03Sav, 300Sav, 7.62x39mm, 308, 7.5Swiss, 30-06, 300WM, 303Brit, 7.62x54R, 8x57mm, 338WM, .380, 9x19mm, 9x23mm, 357 Sig, 38 sp, 357 mag, 38sw, 38-40, 40sw, 10mm, 10.4mm, 401 power mag, 44mag, 45acp, 45Colt, 455 Eley, 452/70, .410, 45/70, 50CB, and 12 ga.

For pistols I get:
1) the Lee set
2) the Lee factory crimp die.

For rifles I get the:
1) Lee collet neck die and then polish the; a) collet, b) collar, c) mandrel/ decapping pin. It does not make more accurate ammo, just smoother reloading. Lately Lee has been polishing those parts better.
2) The Forster FL die and then have the neck honed out at the factory to my specification.
3) The Forster seating die [although the sliding sleeve is off patent now and Redding and others offer it now]. And then I polish the seating stem mouth.

If Forster does not make the dies for a cartridge, like 6.5-06, I get an RCBS set with FL and seater die.

For form dies, I make my own on the lathe.
For neck turning, I make my own mandrel on the lathe and then turn the necks on the lathe.

What does it all mean?
I don't use neck dies much. Bart Bobbitt says he pushes back the shoulder .001" or .002". He uses FL dies with the necks honed out. I am copying him.

[Bart B.]

Rimless bottleneck cases get shorter from head to mouth every time they're fired; they get longer after sizing, moreso with full length sizing than neck only sizing. It's been my observations they shorten a few thousandths from firing but get that much longer plus a few ten-thousandths when full length sized. Some belted bottleneck cases get longer when first fired.

Most benchresters switched from neck only sizing dies to full length sizing dies a few years ago. The smallest groups they shoot are still the same size, but the biggest groups shot with full length sized cases are now a lot smaller. I'm surprised it took them so long to figure that out.

One piece full length sizing dies whose neck diameter's a couple thousandths smaller than a loaded round's neck diameter has proved to make the straightest case necks best centered on the case shoulder. That's what's needed for best accuracy. Bottleneck cases headspacing on their shoulder center up front in the chamber shoulder when fired so the case necks have to be well centered and straight on the case shoulder after they're reloaded. They do not rest on the chamber bottom when fired which is often the belief but in reality is a myth.

Full length bushing dies made by RCBS and Redding are almost as good and the difference is small enough that it'll take a shooter and rifle and ammo that produces no worse than 1/4 MOA groups at 100 yards to tell the difference.

As long as the fired cases' diameters are not reduced more than a couple thousandths or so by the full length sizing die, excellent case life is possible. Several dozen reloads per .308 Win. or .30-06 cases have been done using commercial full length sizing dies with necks opened up a bit on cases fired in SAAMI spec chambers. The critical part is not setting the fired case shoulder back more than .002 inch else there'll be too much case stretching each time it's fired.

As there's no such thing as a perfectly round case or chamber, one needs to ensure there's no interference between case body and chamber walls when the round's positioned for firing. Otherwise, the case mouth will be pushed off center misaligning the bullet with the bore. So, the case body diameter at the shoulder needs to be a few thousandths inch smaller than the chamber diameter at that point.

There has to be enough case head clearance to the bolt face that the bolt doesn't bind on the case head when its closed. Otherwise, the bolt head on't be in the same place for every shot; somthing that degrades accuracy. This is the reason benchresters had to full length size their neck only sized cases every 3 to 4 reloads. The distance from case head to shoulder grew a bit every time it was fired and finally reached the point where the bolt bound up a bit closing on the case head. Their accuracy degraded by 1/10 MOA or more when the bolt bound on closing; way too much for their objectives.

[eldermike]

There are other factors to consider. Benchresters are only moving the necked turned precision cases .002-.003 from fired condition to sized condition. In a typical sporter chamber with commercial brass and off the shelf dies the overall change in brass size from fired to sized could be much more than precision shooters see. Moving brass= working the brass making it harder.

So I guess my best answer is: some guns are hard on brass, others are not. But full length sizing is best for accuracy.

[F. Guffey]

Rimless bottleneck cases get shorter from head to mouth every time they're fired;

Did the case you fired 47 times disappear?

F. Guffey

[old roper]

mardanlin, I use a body die for sizing then neck bushing die and lot of my varmint rifles I'll just neck size with bushing die then I'll FL size with body die when needed.

My 35 WhelenAI and 270Wby they don't make a body die for those so I have to use standard type die for sizing. I take the expander out and size case then I use Sinclair expander mandrel open neck up then use neck bushing die.

Redding been making some small base body dies for the match rd like 6ppc,6br,284 and I'll use some of those also.

I don't mind the extra steps. I've never run any test on case life comparing how I reload to something else so no help on that.

Bottom line is accuracy and I think there enough article on setting up FL sizer no use me try to duplicate any of that.

Well good luck

[Sure Shot Mc Gee]

A FL die would probably be faster because one die does both things but other than that, is there any real difference?

Fl resizing about all it does is swage the entire shell to tolerance and accommodate that cartridges cycling into its chamber.
Neck sizing alone doesn't offer that advantage. The very best accuracy that a home reloader can ask for in a cartridge. (as far as I know of.) Is a cartridge that is has been simply Neck Sized after its been fire formed to its chamber.
If a reloader were to shoot a reduced to low powder charge recipe. Its bullet seated to depth without ever being crimped. Neck sized only. You possibly could get by with as little as 20 piece's of brass for a long long time before their needed replacement. But to get that kind of service from your brass you probably would have to anneal the cases at least once during their life span. The only problem with that theroy. Many don't know how to anneal properly. Doing it wrong basically said. Will no doubt shorten a brass case's lifespan.

[Clark]

F. Guffey
Quote:
Rimless bottleneck cases get shorter from head to mouth every time they're fired;
Did the case you fired 47 times disappear?

F. Guffey

Each time I fire a case, it gets shorter.
When I resize it, it gets longer than it was before I fired it.
If I push the shoulder back much, it gets much longer than it was before I fired it.

With tighter than SAAMI chambers and honed out FL dies, and only pushing back the shoulder .001", I can get so many firings out of a case, I have given up on trimming.

The problem is that rifles I did not headspace, are headspaced all over the place. I need to keep the brass dedicated to one rifle.

Or I can just buy zillions of pieces of brass, and let the empty cases get all mixed up.

[Bart B.]

Yes, Mr. Guffey, that Federal .308 Win. case disappeared after I fired then full length resized it 47 times. The pile of tiny brass particles weighed 171 grains after I cleaned all the powder and primer residue off of them; exactly what the new case did. Took me 3 years to get all the tiny shaving's turned off by the case trimmer superglued back into place. Fortunately, I numbered each one so I could tell which one it needed to be placed next to; just like the stones used in the original London Bridge that was moved from England to Lake Havasu City, Arizona, over the Colorado River could be put back in their original place. I viewed their alignment through a microscope so each one would be a perfect fit to those that were next to them as I positioned them together with micro-tweezers holding each little tiny one.

But I never shot that glued back together case. I didn't trust the superglue to hold those thousands of tiny brass particles intact at the peak pressures it would have to withstand if fired.

[markr]

That sounds really complicated Bart. Pics would be nice.

[F. Guffey]

Is there any difference in case life expectancy when using a FL die as opposed to neck-sizing only for the first firing and then body-sizing when they get hard to chamber? It seems like the brass would need less reshaping that way and would extend the case life, but I'm not sure if that's how it actually works.

If it turns out that I'd rather size the body every time along with the neck, would I be better off having the FL die or the other two separate? A FL die would probably be faster because one die does both things but other than that, is there any real difference?

mardanlin. and no one is curious about the chamber, 308 W, 3.0/06, 270 Winchester? If I did not want to size the neck on a 30/06 case I would use a 8mm57 sizing die, then there is the 35 Whelen for the 338/06 and the 30/06 for the 270 W. AND I have neck sizer dies for most those chambers. Then there is the 6mm/6 for the 25/06.

I start with measuring the chamber length from the shoulder to the bolt face.

F. Guffey

[Sure Shot Mc Gee]

RCBS markets a resizer die called the X-die. You might consider its use over a standard FL die. There are some extra steps that need to be followed when using that resizing die. With its repeated use it offers some degree of prolonged cartridge case life by limiting its occasional trimming. Frankly I never used a X-dies myself. So I'm in no way a expert in its use. But the subject matter is something to consider mardanlin.

[mardanlin]

Sorry guys, the cartridge in question is a 300 WBY Mag. I've noticed they are difficult to chamber so I'm trying to get more use out of these pricey cases.

[F. Guffey]

Sorry guys, the cartridge in question is a 300 WBY Mag. I've noticed they are difficult to chamber so I'm trying to get more use out of these pricey cases.

http://www.saami.org/PubResources/CC...y%20Magnum.pdf

I know I am flawed, when I read about a magnum case that is difficult to chamber I expect to see Larry Willis jumped in to take advantage of the opportunity to make a sale.

Is there any difference in case life expectancy when using a FL die as opposed to neck-sizing only for the first firing and then body-sizing when they get hard to chamber? It seems like the brass would need less reshaping that way and would extend the case life, but I'm not sure if that's how it actually works.

If it turns out that I'd rather size the body every time along with the neck, would I be better off having the FL die or the other two separate? A FL die would probably be faster because one die does both things but other than that, is there any real difference?

You started out in the hypothetical and now you have cases that are difficult to chamber.

A boring story: I started out to form 200 + magnum cases to a wildcat chamber for bench rest type rifles. Of the + cases 40 would not fit the shell holder, for that reason I was asked to bring the other #4 shell holder. I did, I brought 'with me' a gasket cutting ball peen hammer. We set the failed to fit cases aside and formed the other cases. Before we started on the fail to fit cases I measured the case just ahead of the belt and the diameter of the case head at the bottom of the extractor groove. When compared with the cases that fit, the failed to fit had upset case head expansion at the bottom of the extractor groove and ahead of the belt measured from .007" to .013" larger in diameter. Having an Ammo Master and an A2 RCBS sizing the cases should not have been a problem, I did suggest we use a lathe with collets to decrease the diameter of the case in front of the belt, but that did not change the fact the cases had been hammered with heavy loads. the builder decided he would set the failed to fit cases aside.

I also have small base dies for belted cases, and forming dies.

F. Guffey

[Bart B.]

Sure Shot Mc Gee,

What's the difference in how a fired bottleneck case is neck only sized and one that's full length sized regarding how it fits the chamber when it's fired?

[Sure Shot Mc Gee]

What's the difference in how a fired bottleneck case is neck sized and one that's full length sized fits the chamber when it's fired?

Bart Oh Bart. How's {FL grows less in length} sound?_

[Bart B.]

Sounds like an answer from someone who doesn't know what the difference is that's important for accuracy when the round's fired.

You're answer relates to after it's fired

Try again starting when the firing pin fires the primer. And note that full length sized cases typically shorten more in length after they're fired than neck only sized ones.

[Sure Shot Mc Gee]

Bart B. Frankly. As commented. You asked me question I then answered it graciously and to the point. Its appropriate at this time that you direct your learned idea's and questions to the individual who open this thread.

[Bart B.]

Sure Shot, if you disagree with or don't understand what I put in post 4 above, that's fine by me.

[603Country]

Mandarlin, while the rest of them snap and snarl, I'll suggest that you FL size, but only to the point that the die pushes the case shoulder back enough that the case chambers without resistance. It's called Partial Full Length Resizing, and that method will allow you to headspace off of the shoulder and not the belt. Your cases should last longer and you might also improve accuracy.

You can do the above with any standard FL sizing die, but a somewhat better approach (for brass life and possibly for better accuracy) would be to do the Partial FL resizing with a Redding FL Type S bushing die, then you can vary case neck tension with different size bushings. And, that Redding die can also be used as a body die if you use it without the bushing.

[F. Guffey]

[QUOTE] [Sounds like an answer from someone who doesn't know what the difference is that's important for accuracy when the round's fired.

You're answer relates to after it's fired

Try again starting when the firing pin fires the primer. And note that full length sized cases typically shorten more in length after they're fired than neck only sized ones.
__________________/QUOTE]

Bart B. that response is just plain rude, try the firing pin strike the primer and drives the bullet, case and powder forward until the shoulder of the case strikes the shoulder of the chamber etc.

And then there is that story about the case getting shorter ever time You fire it. Never do you give a number as in 'by how much'. I ask you 'by how much' your 47 time fired case shortened. I ask because you claimed the case shortened every time you shot it. And your claim? You used full loads.

I believe you take your self too serious, or you take your self more serious than I do. The silliest and most unimportant bit of information a reloader can holler about is the length of the case, as I always say from the end of the neck to the head of the case.

I do appreciate Clark not responding in a manner rather rude when responding to the 'case gets shorter when fired', it could be said he did not respond in an immature manner.

F. Guffey

[Bart B.]

603, partial full length sizing means only the case body and most of its neck is sized. The case shoulder is typically moved forward a little as it never touches the die's shoulder.

Your suggestion to use a full length bushing die is good.

Guffey, read post 4 regarding how much case length changes when fired then sized.

[F. Guffey]

603, partial full length sizing means only the case body and most of its neck is sized. The case shoulder is typically moved forward a little as it never touches the die's shoulder.

Your suggestion to use a full length bushing die is good.

Bart B. trying to work with you on this, and, NOW! I see the problem, you spend too much time with the 'firing pin strikes the primer etc. etc.' and not enough time on the important sequence of events.

When sizing a case the diameter of the case is reduced, when the diameter of the case is reduced the shoulder of the case moves forward, and by the experts it is claimed the shoulder takes on a slight radius, meaning? the case gets longer from the shoulder to the head of the case. So? Partial full length sizing has some flaws.

Partial full length sizing has too many words in the description, full length sizing is full length sizing, as in returning the case to minimum length. then there is adjusting the die to avoid returning the case to minimum length. It sounds great, you day you bump the shoulder .001" and in the same sentence you claim you full length size, to me? That is a conflict. And, I ask "How do you do that?"

Life and reloading is not that complicated or confusion, I use the companion tool to the press, the feeler gage. When I full length size I screw the die down to the shell holder with an additional 1/4 turn or 90 Degree or .0178", even then there is no guarantee the press is going to win by sizing the case because the case could have more resistance to sizing than the press can overcome. More resistance to sizing will require an increase in the presses ability to overcome the resistance. That is accomplished with an additional 1/4 turn of the die to .0357"

I get around all of the adjustments by not insisting the die be screwed down the additional fraction of a turn. I adjust the die to or off the shell holder, I make those adjustment with a feeler gage.

When I size the case with the feeler gage adjustment the case is sized, all of the case contacts the body of the die, all of the shoulder makes contact with the shoulder of the die, and all of the neck is sized.

Then there is verify, verify is like a foreign language to most reloaders.

F. Guffey

[603Country]

Bart, if a fellow uses that FL die so that it does just push the shoulder back a slight amount, it's still Partial Resizing. Maybe a better term would be "Almost Full Length Resizing".

If you 'lightly' partial resize a tapered case (270, 220) the shoulder won't be pushed forward. It's on the not-so-tapered cases where the die does touch and constrict the upper part of the case and cause the shoulder to be pushed forward. Partial resizing to a minor degree works great on my 270 and my 223, but I have to set the die down almost all the way on the 260 and 223 to push that shoulder back. But even then the die isn't set down all the way, so it remains a 'partial' resize.

What seems to work the absolute best for me is to use a Lee Collet die for most case resizing and then use a Redding body die to push the shoulder back when it's needed. That will maximize case life, which is what the OP was wanting info on. But...I don't think he can get a Lee Collet Die for his caliber. So for the OP, I do think that he should get the Redding Type S FL Bushing Die and not FL resize to the maximum, but just enough to push the shoulder back the desired amount. Mr Guffey would have the data to the thousandth, but all I can say is that the die should be set so that it does not quite touch the shell holder - probably less than the thickness of a nickel. Depends on the case and how it was fireformed. I have to determine the die setting by trial and error, but it doesn't take long to do that, and once it's set you never have to reset it again (for that rifle).

Bottom line on case life is that the OP should not FL resize to the maximum. He wants to headspace on the shoulder and not the belt. And call it what we will, but that is some degree of Partial FL Resizing or 'almost FL Resizing'.