I've been loading for a couple of years and to this point all of my case sizing has been full length. My next 2 projects are a Remington M700 .270 and a Kimber M84 .308. I'm thinking of either partial sizing or neck sizing only. What are the pro's and cons of all 3 methods?

better go get some milk duds too!

Ah, c'mon Woods. Give the guy a break. It's a very legitimate question for someone who has no experience in the matter.

Yes, there are many answers to these questions and I don't feel like I am up to the task of answering the question in its entirety, but I'll kick it off. I'm sure someone on here will be more than willing to elaborate.

Full Length
PROS

-works every time (less chance of having a stiff bolt to close or open)
-good for when reliability is more important than extreme accuracy
-Semi-automatic rifles generally prefer full-length or even "small base" loaded ammunition for reliability.

CONS

-without fine tuning, a tight "crush fit" is not achieved and some play is found between the bolt face and the datum line of the cartridge.
-The theoretical center line of the bullet/cartridge may not be in line with the center of the bore
-can lead to shorter case life due to "work hardening" the brass

Partial Sizing

Somewhere in between the above and below methods with a few nuisances of each

Neck Sizing Only
PROS

-great for squeezing the last bit of accuracy out of a bolt gun (ie. the benchrest crowd)
-once case is fireformed, it allows for a nearly perfect tight fit of the case in the chamber, thus theoretically aligning the bullet/cartridge with the centerline of the bore.
-usually get longer case life
-bushing style neck sizing dies give you more control over neck tension (although Redding does make FL bushing dies too now)
-Takes much less effort to work the press than full length sizing (less lubrication too)
-Theoretically works well in belted magnum cases that headspace on the rim of the belt rather than the shoulder. The neck sizing only method can be used to headspace the belted magnums on the shoulder instead once the shoulder has been blown out to full length.

CONS

-Can be less forgiving (reliable) in tight chambers or semi-automatic rifles
-Will need to occasionally "bump" the shoulder back a little once the case lengthens and the bolt is difficult or unable to open/close with ease.
-Your ammo may not be interchangeable between other rifles due to your rifle's different chamber dimensions of fireformed loads, despite being of the same caliber.

That's all I got for now. Again, this list is no where near all-encompassing, but it should get the party started...

Good luck!

Kenati, excellent explanation.



Chuck

You're right Kenati and a good post

Hey dlile, welcome to AR

There will be some disagreement on this one and all will be right in one way or the other.

New cases are considerably smaller than the chamber and when fired they will expand and then "spring back" a little. The amount of springback decreases due to work hardening until it will be perfectly fireformed to the size of your chamber. When it is fully expanded the case will begin to bind because of contact at the shoulder and be harder to chamber or have a "crush fit". A severe crush fit is not preferable in a hunting situation as it may cause problems at an inopportune moment. That is the reason neck sizing only is not a viable option for a hunting gun.

There is a certain period when you can neck size only without a crush fit. For example in a 30-06 I have the shoulder of the case went through the following measurements taken with the Hornady Head & Shoulder Gauge when neck sized only:

New case - 2.040"
Once fired - 2.0485"
Twice fired - 2.050"
3 times fired - 2.0510" (slight crush fit)
4 times fired - 2.0515" (crush fit)

At this point you can no longer neck size only unless you wish to grind the case into the chamber and wear your lugs out. You should push the shoulder back, but you should only push them back a minimal amount to relieve the crush fit. The reason to only push it back the least amount possible is to decrease the amount of subsequent expansion and sizing and increase your brass life.

Definitions vary, but the consensus of opinion around here is that partial full length resizing is sizing the case so that there is minimal contact at the shoulder or the shoulder of the case is very close to contact with the chamber shoulder. In the example above that range would be from 2.0505" to 2.051".

Until you get to the point where you can partial full length resize, your case is essentially in flux and you can not resize your case to the exact same size everytime to the .001". Consistancy is the essence of accuracy so once you get to the point where you can push the shoulder back to the exact same point and size the case body to the same dimensions (partial full length resizing), then you have the best chance for repetitive accuracy.

Full length resizing is not taking the case back to the original dimensions (that would be way too small) but is rather sizing the neck, pushing the shoulder back beyond all possibility of contact at the shoulder and sizing the case body to your die dimensions. As Kenati said that is loose in your chamber and not best for accuracy.

Woods & Kenati,

Thanks for your help.

I partial sized a 1x fired .270 case to see what the dimensions changed to but I did not have a way to check shoulder set back so I was stuck checking case OAL and case diameter in various spots. Now I know that there is a specific tool for this type of measurement, I'm going to get one.

Lastly, my father once told me that there are no stupid questions, only stupid people that ask questions

Thanks again and have a good New Year.

Now, I only full length size cases. I get pretty good accuracy doing this, like three shots at 100 yards that drop into 1/2" groups, or less.
Feeding is most important to me.

If you want the best of all worlds I can highly recomend a lee collet die followed by a redding body die if needed. This is one sweet way to make really straight ammo that is sized just enough to chamber freely during all hunting conditions.

DMB,

To this point I've only been full length resizing. I have a 25-06 that will shoot ~.400" 3 shot groups if I do my part. I'm just trying to experiment and increase my knowledge and understanding of what my toys can do.

You came to the right place for information. If you do a search here you will find this subject has been discussed many times over the years. One thing is for sure. You have lots of options when loading.

Dwight,

Waaaaayyyyy to many options. This is worse than walking into Toys R Us as a kid But it's a lot more fun

In case there are folks reading this thread who are beginners or are thinking about starting handloading:

One thing that we need to keep in mind is that there is no such thing as neck sizing ONLY. New or newly annealed brass should be FL sized. At some point the neck sized cases will become work hardened just like FL sized brass. We like to think that happens a whole lot slower when neck sizing is used, but the hardening happens.

Cases will rebound less and less until at some point they are not headspacing and the rifle's bolt gets hard to close. There are companies now making "body bump" dies to reset the shoulder to base length of your neck sized brass. Since I anneal after every 5 firings, I don't see a need for such a die, but people are buying them.

I think someone has already mentioned that partial sizing has the drawbacks inherent in both neck and FL sizing. I've never done it; it's not exact enough for my use.

Don't be expecting to get BR accuracy from a factory gun just because you've neck sized the cases 3 times. These days, neck sizing is not as popular in loading BR rounds, at least for 100 and 200 yard use, as it was back when we were shooting accurized factory rifles. I think many if not most, are jam seating in a FL sized case. Chambers are so true and tight in today's custom BR rifles that you hardly work a 6PPC or 6BR case at all. I don't know anyone here that uses neck sizing in those calibers. Still, not everything done in making up BR loads translates to general reloading.

If I were going to be loading for plinking or hunting with a .270 or .308 I would probably use a Forster or Redding 3 die bushing set (FL, neck, and seater) if I thought I would be requiring the best accuracy over 300 yards. If not, I'd buy the Lee dies. With the former two, you have more control over neck tension than with the latter. You can get to be pretty good at judging neck tension using the Lee collet style neck sizer, but it takes some practice.

I have used all the above and still do. I have a couple of non-match rifles that I like to see how small a group I can get at 2 or 300 yards and I use the bushing dies for them. I have a couple more that I just take out to the range to try to ring the gongs with and the Lee dies are perfectly good for them, and if truth were told, they probably do just as good a job. Loads for my match rifles don't get neck sized.

quote:

Originally posted by amamnn:

I think someone has already mentioned that partial sizing has the drawbacks inherent in both neck and FL sizing. I've never done it; it's not exact enough for my use.

This is an illustration of how there are not set definitions of the 3 types of sizing (NS, PFLR & FL). As in the explanation above I have found the majority of posters have the following definitions:

NS - Neck Sizing - sizing all or part of the neck, no contact or sizing of the case body and shoulder not pushed back

PFLR - Partial Full Length Resizing - sizing all or part of the neck (you can size only part of the neck with various methods), pushing the shoulder back so that there is some contact from a very very slight crush fit to a crush fit and sizing the case body

FL - Full Length - sizing all of the case neck, pushing the shoulder back so there is no contact at the shoulder and sizing the case body. Essentially clearance around the case and chamber all around.

PFLR is just as exact everytime and when I PFLR I position the shoulder to exact same place everytime to the nearest .001". With NS the shoulder is in flux unless you are NS and leaving the shoulder for a severe crush fit. Then you would be setting the size of the case the same each time but you would have to put up with the crush fit. With FL resizing you could set the case parameters to the same dimensions each time but it is not more exact than either of the 2 other methods and you would have to put up with the slop in the chamber.

quote:

Originally posted by kraky:
If you want the best of all worlds I can highly recomend a lee collet die followed by a redding body die if needed. This is one sweet way to make really straight ammo that is sized just enough to chamber freely during all hunting conditions.

+2, right as usual kraky

Try thinking of it like this:

1. FL sizing is done to SAAMI specs. It has nothing to do with how well a SAAMI cartridge may or may not fit your chamber but it does insure the cartridge will fit any other rifle chambered to SAAMI specs.

2. P-FL is the reloaders advantage over factory ammo (SAAMI specs) because it allows us to size as needed for our specific rifle.

3. Neck sizing should always be done with a Lee Collet Neck Sizer because only it can be absolutely certain of working a neck the minimum amount needed AND that the resulting neck is straight.

I DO WISH LEE WOULD MACHINE THE GUTS OF THOSE THINGS MORE SMOOTHLY!

I did some experiments shooting and resizing today with the Lee Collet die for .223, and measuring concentricity.

Sometimes the Lee Collet worked great, and sometimes eccentric.

I took the Lee Collet apart and there was a rough surface on the collet and on the cup where they fit together and slip under high force.
There was also a metal chip inside from the manufacture of the relatively unused die.

I put both collet die parts in the lathe and polished them with TH2 grade abrasive paper [very fine].

I cleaned the parts and lubed them.
Then I got more consistent concentricity.

Further, the FL Redding "S" die .246" bushing and FL Forster .246" honed neck do well with wimpy loads [34kpsi] and medium loads [47kpsi], but with hot loads [66kpsi], the brass grows .005" while just setting the shoulder back .001".

The brass growth is not a problem with hot loads and the Lee Collet die ~0.0005"/ firing, or 10 times better than the FL dies.

I may have to FL size the AR15 fired brass and set the shoulder back .001", trim, and chamfer.
Because there is no other way to get it to fit in my Ruger #1
But then after I fire it in my Ruger #1, I will just size it with the Lee Collet die for the next 10 hot loads in the #1

quote:

The brass growth is not a problem with hot loads and the Lee Collet die ~0.0005"/ firing, or 10 times better than the FL dies.

The Redding type S neck die will probably produce the same results as the Lee collet die.
I have used the same bushing arrangement in Wilson neck bushing dies with 2 6X47s and have been able to ignore case length growth. Cases eventually get a well defined pressure ring from being fired more than 20 times but the case length barely changes.

quote:

Originally posted by SR4759:

The Redding type S neck die will probably produce the same results as the Lee collet die.

If you neck turn

quote:

The Redding type S neck die will probably produce the same results as the Lee collet die.

Not at all. Totally different systems, no comparision between them other than both are neck sizers.

quote:

Originally posted by Jim C. <><:

quote:

The Redding type S neck die will probably produce the same results as the Lee collet die.

Not at all. Totally different systems, no comparision between them other than both are neck sizers.

The type S neck die has the same bushing arrangement as the Wilson die that everyone raves about. The Wilson bushings do have a larger corner radius than the Redding dies. I think that ensures the neck sizes down more concentrically. I get excellent results from the 6X47 without neck turning since the factory 40X barrels are made with the larger neck diameter. There is nothing like a good barrel to make all the reloading techniques arguments moot.

I used to be a big fan of PFL, but still had some runout problems because the die was not squaring itself against the shellholder. Redding competition shellholders fixed that problem, and give you the best of both FL and PFL resizing.

Also, I'm with kraky and woods on a Lee collet die followed by a Redding body die- they are the cat's meow.