Home Forums Hunting & Shooting Ask The Gunwriters Neck Sizing vs FL Sizing

I'm relatively new to reloading and have only used FL sizing dies but as I read more and more, it sounds like I only need to neck size. Is this preferred for brass life and accuracy? Do you get better accuracy from only neck sizing since the brass is formed to that chamber?

I only have one rifle per caliber so the brass is only shot from one rifle.

Should I start getting neck sizing dies and not use the FL dies? All of my die sets are FL right now


Also, I have a 25-270wsm that I shoot. Once the brass if FL sized from 270wsm and shot from the rifle, I can neck size then, correct? Would this require a custom neck sizing die? or would any 25 cal neck sizing die work?

Thanks all!

I'll add to what Mathman said. As far as accuracy, it depends. I have some rifles that I can make straighter ammo. (less runout) by neck sizing, and others that are straighter using an FL die to minimally size the case. It depends on the brass, your chamber, and the die. Learn how to minimally size if you use a FL die.

I would agree that a bushing die is best because it allows you to select the right bushing to get just enough neck tension, without needing to use the expander ball to expand the necks back to the right size after going into the die. The expander ball can pull the necks out of alignment.

You can get full-length bushing dies too, that size the case and allow you to use bushings to get the right neck tension without using the expander ball.

Clear as mud, eh?

This is one of those situations when you wish you had the questioner at your loading bench where all could be made clear in a very few minutes.

Need to read a whole lot more. Might include some specifics like Fred Sinclair's out of print guide, Precision Shooting's out of print guides and Zediker's various guides. Start with Zediker's latest book and tolerate the prose style as necessary. For hunters with factory chambers there is little need and negligible benefit from applying short range bench rest techniques that do work beautifully with custom chambers and neck turned cases.

Only doesn't work at all. Notice FREX that Redding will package a neck sizer along with a shoulder bumper because both are eventually necessary. Preferred? sometimes not always. Many will choose to full length size for autoloaders, break actions and other firearms where ample clearance helps feeding and extracting.Better accuracy? Maybe. Certainly for short range bench rest in short range bench rest chambers in short range bench rest rifles not necessarily in other rifles. Say the neck is off center with respect to the chamber then fitting the case followed by rotating the case in the chamber next time will impact accuracy adversely. Sometimes having the case sit on the bottom of the chamber is better. As noted not using FL dies in the sense of never using FL dies is not an option. From time to time shoulder bump is necessary. Also reading up on the dreaded doughnut is not only a good idea it's eventually essential after neck sizing only.

Likely enough a bushing neck sizing die made for the .270 WSM - assuming such exists - will work with the bushing of your choice. A neck sizing die made for .25-20 surely would not. There have in the long ago past been purely neck sizing dies made and marketed as somewhat close to universal. These are no long common in the market place.

Bottom line. A little learning is still a dangerous thing. Like a low hours motorcyclist or a low hours pilot it's a time of not knowing what isn't known. Much safer sticking to what works and building hours while researching and reading and building a knowledge base.

yep... clear as mud!

So, I'll read up on the Lee Collet dies or the interchangeable ones you speak of.

How do you minimally size with FL dies? The dies I have now size and decap in one operation. Separate decapper?


I wish I could be at the bench to learn some of this....

I full length size, because I have multiples of some calibers.

By not following the directions that come with most of them. Those directions lead to brass sized down enough so it will work in almost any chamber, not just the one it came out of. Minimally sizing means adjusting the die down into the press just enough so the sized brass smoothly chambers in the rifle from whence it came.

All I can testify to is my own experiences. I load for the 243, 7mag, and 7-08 presently. I had used either RCBS or Redding FL sizing dies and seaters up until I started using Lee collet neck sizing dies and Lee bullet seaters. My runout decreased in every instance, and I got notably more accurate and consistent loads because of it. I'll use neck sizers over FL sizers every time.

For years I was very anal, neck sized with Redding competition neck dies, used a jeweler's scale with tweezers (+/- 0.05gr), competition seating dies, etc. Even tried the Lee's stuff. Then last year I used a guy to work up loads: I can't anymore at my house- 8 horses, cows, etc and going to the range in the summer heat was impractical. Anyway, he works up POI loads, not groups. He shoots one, takes the rifle inside lets it cool down, shoots again, etc.

He uses RCBS FL dies with the generic seaters and duplicates the one holers I had shot for years.

I have since gone to Whidden custom non bushing dies and have been very happy.

Bottom line- it ain't rocket science as long as you do everything the same (precision is repeatability), but absolutely do what satisfies the 90% between your ears. That's all that counts.

CJC73,

I highly recommend neck sizing

I would recommend the lee neck die over the bushing neck die for several reasons

1. The lee die sizes from the inside of the neck. If the neck wall of your brass isn't uniform thickness it doesn't effect the straightness of the neck. Because of this you don't have to turn necks which doesn't help anyway if your not shooting a custom rifle.

2. Bushing dies size from the outside of the neck. If you don't turn your necks inconsistency in neck wall thickness will leave you with a crooked neck. Again, why waste your time turning necks when you won't see it on paper in a factory chambered rifle.

"A FEW OTHER REASONS TO USE THE LEE NECK DIE"

The lee collett neck die you don't use lube on the case so you have no nasty mess to clean up 😀😀😀
The lee die costs much less
The lee die produces less run out if your not neck turning (less run out usually translates to improved accuracy)

A FEW THINGS YOU SHOULD KNOW

The lee neck die deprimes and sizes the neck at the same time
The instructions are not the best so if you decide to go that route come ask a few more questions.
You can usually neck size 4 or 5 times before you will have to full length size to push the shoulder back so you can still chamber your brass. In other words keep your full length dies because you will still need them on occasion.





Trystan

It is more commonly known as "Partial full length" sizing.

Mathman's description of how, is accurate. Leave the die UP a couple of turns from bottoming out.
Use 1 (one) case at first, run thru die, check to see IF it will chamber.
Adjust die down a little & repeat. It's a matter of sizing the cases in YOUR die for YOUR chamber.

Being slow & careful you can get the adjustment set to where you can just barely feel resistance when you
close the bolt. Carefully set the lock ring and check 2-3 more cases. Adjust IF necessary.

I've used P Fl sizing for many years. If done correctly case life is excellent.

** Some guys say they never lock the ring/die.

** I would not consider going thru this procedure every time I loaded ammo.

You must decide for yourself.
Good Luck

Jerry

I'll repeat there's a lot of reading to do starting with Earl Naramore and Phil Sharpe up through George Nonte and John Wooters with a nod to Bob Hagel not forgetting Pet Loads to wind up with Zediker - Top Grade Ammo is his latest - and Barsness. A good selection is available at libraries or interlibrary loans.

I started with a 310 tool, sometimes decapping with a finishing nail and a hammer so I could fiddle with the primer pocket. There is no reason to be hung up on equipment when good results can be had with the simplest of equipment and careful work. There is also no reason to use anything but the most efficient for the purpose - no prizes for cheaper equipment and skill is hard to buy with money.

FWIW I only ever neck size. I haven't full length sized any brass for longer than I remember. In fact when I first started out, nearly 40 years ago, neck sizing was all I was equipped to do.

I reload for a variety of firearms, including break-action, lever action and falling block, as well as bolt actions with front locking lugs and rear. To the extent relevant some use rimmed and some rimless.

I use a mix of Lee Collet dies (which I prefer) and others.

I seem to get good case life - have batches of brass that went past 30-odd reloading cycles before I stopped counting, without ever being FL sized. They do need necks annealed every now and again though.

It seems to me that the greater degree of cold-working inherent to FL sizing may not augur well for case life (though of course you can anneal the neck and shoulder where the bulk of the working occurs), but other than for .303 in my Lee Enfields I haven't run the experiment. With the .303s I found that FL sizing had a definite adverse effect on case life, but that is a bit of a special case: these chambers are cut pretty loose, and generous in the headspace, and so if you FL size you tend to see not only a lot of deformation but also stretching and, quite quickly, case separations. I avoid problems in this regard by taking care to fireform symmetrically, by using a narrow strip of tape or o-ring around the case in front of the rim, so that the case will be pushed hard back against the boltface and expand to fill the chamber. After that I neck size only, and the case headspaces off the shoulder not the rim, avoiding the stretching problem.

I have often read people talk about the need to "push the shoulder back a bit" after a few reloading cycles, or to FL size to ensure that the case will chamber. I've never really seen a need for either. It seems to me that if a case came out of the chamber it simply has to fit back in again, unless you do something to it in the meantime. In fact, given that brass obeys Hooke's law within its elastic limits, the case is always going to end up smaller than the chamber, and it sure can't end up bigger.

The only two likely ways I can see why a case you fired in a chamber won't go back in again easily are either you did something to it which altered its dimensions, in the reloading process, or the chamber was loose or out of round, so the case is no longer symmetrical, and won't fit back in unless oriented the same way as it was when fired. I've only seen evidence for the second one in very loose chambers. I suspect that more often than not it is a result of the sizing method, and that the need to push the shoulder back every now and again is because you were inadvertently pushing it forward due to your reloading process, such as by the effect of partial sizing or by dragging from an expander.

Me too
In fact I don't even own FLS dies for a lot of my guns.
The simple way to see that FL sizing isn't necessary is to rechamber the fired brass.
It will rechamber easily unless your gun is seriously faulty.

Simply, not true. Each time a cartridge case is fired, it loses some elasticity. Eventually, after several firings/loadings neck sizing only, it WILL become difficult to chamber even in the best made guns on the planet.

Thanks guys... i'll experiment with a neck sizer on one and see how it goes as well as Partial FL sizing. and i like the idea of not using lube for neck sizing.

all my rifles are bolt actions.

I'll continue on and experience will grow and learn new things all the time.

Lee also sells just sells the collet die alone.........

or in a 2 pc set w/seater.........good stuff.......

https://www.midwayusa.com/product/1011198814/lee-collet-neck-sizer-die

CJ,
Try PFLR (Partial Full Length Resizing) first. When neck sizing only after a number of firings some cases will "springback" more than others eventually some cases will chamber easily while others won't, and eventually you'll have to bump the shoulders back on all the brass anyway.

With some of my rifles I get very low runout with PFLR, others I use neck sizing and bump the shoulders back when needed.

I don't want to hijack the thread, but what's the difference between the seater die that comes in Lee's Pacesetter three-die set, and the "dead length seater die" that comes with the collet set? Is it simply that one has the capacity to crimp while the other does not?

Thanks

RM