Neck sizing or full length problems. Advice needed

[artbosco]

Hi I'm new to comps and this weekend did my first F T/R comp. First two rounds were ok getting 5th in the second match. In these rounds I used ammo that had been full sized before reloading. The next two rounds were no where near as good, scores were 20 points down! The only difference was the ammo was neck sized, not FL, in the last two rounds.

Tested the remaining ammo this morning and the first ammo groups very well (FL), the second, neck sized ammo won't. Both lots of ammo are Lapua cases, 46.8 gr varget, 155.5 bergers. What have I done wrong?

You haven't done anything wrong. You learned that F/L sizing trumps the half measure of neck sizing all the time because it promotes consistency by bring the ENTIRE case back to the designer's original specs. Accuracy is all about consistency, consistency and consistency which promotes tighter groups and better scoring.

 

[mikecr]

Outdoorsman, what you're saying does not apply across the board.
A modern design in cartridge(not a 308 or 30-06), managed well in reloading(not oversized), holds more consistent dimensions and capacity than typical FL sized cases. They are also lower in runout, needing less trimming, and less annealing. All of which should be desired for those who can do it(takes a plan).

FL sizing doesn't 'trump' anything.

 

[tisme]

I've been at my bench with dies, gauges and brass. My heads now spinning.

The brass that is very accurate in my rifle when fired measures (with a brass tube over the neck onto the shoulder) 2.447. A case from the die set the same as when I was shooting was 2.438, so I was bumping the shoulder back .009. This goes into the chamber easy with no resistance.

Backing the die off so the OAL is 2.440 gives me a small amount of resistance as the bolt is closed. Now the part the making my head spin. Resizing with my neck die set the same as when I made the bad ammo up bumps the shoulder back! OAL of neck sized case is 2.441. .0006 bumped back.

I think I'll forget about neck sizing and have a play with FL and head space. Thanks for all the very good advice, I have learnt a lot through all the input.

Some info on the rifle. It started life as a std Howa1500 but last year I had a Bartlin 32" barrel put on it, the action was also checked. It has a Jo West stock thats bedded.

 

[CatShooter]

Outdoorsman, what you're saying does not apply across the board.
A modern design in cartridge(not a 308 or 30-06), managed well in reloading(not oversized), holds more consistent dimensions and capacity than typical FL sized cases. They are also lower in runout, needing less trimming, and less annealing. All of which should be desired for those who can do it(takes a plan).

FL sizing doesn't 'trump' anything.

+1

I have two bench grade guns I don't even own a FL die for. They both shoot in the teens to twos most of the time.

Whatever way you size, that is the way you need to work up the loads for.

FL sizing became vogue, only when PB bench started shooting fast and couldn't deal with the torque of a case with any crush.

 

[Bart B.]

From what I've gleaned from the stoolshooters who've switched from neck only to full length sizing is, their smallest groups are still the same small sizes. But their largest ones are now smaller. Group aggregates' have smaller numbers. One competitive discipline's top scoring folks learned that back in the 1950's.

'Tis my opinion that the smallest groups shot by anyone or anything happen when one of two things happen. One way is everything is perfect; zero tolerance, zero spread in all the numbers of aiming errors, size, weight, shape movement, and forces as well as the force axis across the shooter, rifle and ammo. The other way is all those variables cancel each other out perfectly. How does one tell which one it is?

And the largest groups happen when all those variables add up in one direction for the shots striking furthest from group center.

 

[Shynloco]

Good Morning to All,
Ok guys, now this discussion is starting to make my head spin simply because what I see going on is not only opinion and methods each of you use, but now a comparison of "Apples to Oranges" has emerged. Let me explain as to the way I see it.

1. Most folks who strictly Neck Size, are interested not only in accuracy, but in the life of their brass.

2. Most folks who FL resize could care less about the life of their brass and are interested in both accuracy and total uniformity of each piece of brass.

3. And oft times, it strikes me in these very types of discussions about the advantages of FL resiziing vs Neck sizing, not all folks in this discussion are using the same types and makes of dies and brass. Hence those who have and use SAAMI spec dies and not custom ones, don't necessarily get the same results with their final product. Hence my comment about mixing Apple to Oranges.

4. I have to believe that in order to find out which works best for each individual reloader, you gotta try each method out that anyone advocates and see what works best for you and keep in mind your end game which may well be the deciding factor. By that I mean I reload strictly for fun and pleasure. That means in my 6br (with a SAAMI Spec chamber) I use to neck sizing die strictly (measure each casinh for shoulder position each time) and easily would get 30 -40 reloads out of my Lapua brass (before any necks cracked), having annealed my brass maybe once over that period. But I see some of my friends who do compete (with a custom tight chamber) FL resize each time, with some annealing after every firing and some every third time).

5. I guess what I'm saying is there is no hard and fast rule that works for everybody. But these discussions are so darn informative , if for no other reason, than to read the justification each of you lay down to support your position. And more often than not, I find my relating to what you've said because I've experienced that very, sometimes delicate issue, in one of the calibers I reload for. In short, comments do trigger thoughts of ways to improve oine's methods of resizing and prepping brass for better accuracy.

Just my thoughts but love reading all the comments nonetheless.

Alex

P.S. I need to modify one thing that CatShooter has pointed out to me which I was unaware of. And that is that there are no "SAAMI spec Br chambers." I was thinking all along that since I have have a Savage 6mmbr that is an 'across the counter" rifle, that it had a SAAMI spec as I "ASSUMED" (major mistake) that SAAMI was the standard by which any commercial rifle would adhere to. So to my point in my original post, so many little, but correct things, can be learned from these discussions and to that extend, this old FART has learned something new today. So thx to Catshooter for that.

 

[jo191145]

I've never seen any difference in brass life between fl and neck sizing. It's all in getting that die adjusted correctly.
A little friction on the shoulders (headspace) is ok for accuracy but I prefer a little space after the first firingforming.
A little friction on the webs and toss the gun in the case and go home. The days done.
I FL everything every time now. A reformed neck sizer.

Fwiw in my ppc fl sized brass requires .2 gns more powder to bug hole compared to neck sizing which is only good for one firing anyway. Opposite of the usual thought process.
My assumption is that .2 gns of powder is used to expand the brass compared to NS.
JMO

 

[seymour fish]

Eric, I am interested in your comment about the chamber being the arbiter of case capacity, and wonder if you have seen a difference in MV using fireformed brass neck-sized vs. full-length sized with exactly the same neck tension, the former with perhaps a grain more h2o capacity in its static state. It seems the extra bit of case expansion would soften the initial pressure rise, perhaps not enough to be meaningful, but just curious. Seymour

 

[artbosco]

NEVER NEVER NEVER just neck size EVER! Here's what happens.

When you just neck size, the body of the case continues to expand at each firing [interior volume also increases] until, at some point, you will not be able to seat the case in the chamber.

Then, you have to bring the body back into specs to be able to seat the round. Most who neck size, also use a body die. They have to at some point, or they throw the brass away. In order to bring the body back into specs you OVER WORK the brass by having to move it a longer distance to meet specs. It becomes a perpetual, alternating process, between neck sizing, and body sizing. There is nothing consistent about it.

Accuracy is all about consistency, consistency, and consistency. There is nothing consistent about working one part of the case many times and another part a few times. Over Working brass has nothing to do with frequency and has everything to do with how far brass has to be moved to bring it back into the original designer's dimensions.

FULL LENGTH SIZING, which should be done each and every time you reload, with a properly dimensioned Die, moves the case's ENTIRE dimensions from .0005" to no more than .001" to bring it back into specs. And, as an added benefit, you only need one die to do that.

When brass is moved miniscule distances there is NO Over Working and consistency, consistency, and consistency is maintained, which promotes accuracy.

So, if someone suggests neck sizing only, don't just walk away from them, run from them as fast as you can!

Purchase a properly dimensioned, Full Length Die [preferably with bushing capability] and use it each and every time you resize. It will serve you well and prevent a whole host of problems.

 

[Bart B.]

Outdoorsman, how would you like your Atta-Boy trophy shipped to you?

If one "accurately" measures both case and chamber out of round conditions in the body area, it should be easy to see that as neck only sized case bodies get big enough in their "average" body diameters, they'll soon interfere with the chamber body depending on how they're indexed in the chamber.

Case necks float free in chamber necks when the primer fires. What's wrong with case bodies floating free in chamber body areas? Except, naturally, at their back end that's pressed against the chamber wall by the extractor's lip pusing on the cases extractor groove. But that only misaligns the back end of the case a thousandth or so.

 

[CatShooter]

NEVER NEVER NEVER just neck size EVER! Here's what happens.

When you just neck size, the body of the case continues to expand at each firing [interior volume also increases] until, at some point, you will not be able to seat the case in the chamber.

Then, you have to bring the body back into specs to be able to seat the round. Most who neck size, also use a body die. They have to at some point, or they throw the brass away. In order to bring the body back into specs you OVER WORK the brass by having to move it a longer distance to meet specs. It becomes a perpetual, alternating process, between neck sizing, and body sizing. There is nothing consistent about it.

Accuracy is all about consistency, consistency, and consistency. There is nothing consistent about working one part of the case many times and another part a few times. Over Working brass has nothing to do with frequency and has everything to do with how far brass has to be moved to bring it back into the original designer's dimensions.

FULL LENGTH SIZING, which should be done each and every time you reload, with a properly dimensioned Die, moves the case's ENTIRE dimensions from .0005" to no more than .001" to bring it back into specs. And, as an added benefit, you only need one die to do that.

When brass is moved miniscule distances there is NO Over Working and consistency, consistency, and consistency is maintained, which promotes accuracy.

So, if someone suggests neck sizing only, don't just walk away from them, run from them as fast as you can!

Purchase a properly dimensioned, Full Length Die [preferably with bushing capability] and use it each and every time you resize. It will serve you well and prevent a whole host of problems.

I neck size and very rarely FL size - I recently bought a FL die to size a bunch of fired brass that was given to me, for a bench gun I have owned for ~35 years.

I don't own a FL die for most of my rifles... and I don't have ANY of the problems you describe.

And I can assure you that I have loaded more than you, and for longer than you, and for more different cartridges than you.

I think what you say is your theories, cuz it does not match all situations.

If you have these problems, then solve them your way, but your way is not the only way.

 

[fguffey]

Thanks for the advice really appreciated
I think your both right I only have RCBS dies and the instructions say screw in down until ............... I have no idea how far I bump the shoulder back.

What dies should I get

tisme, there are not many dies I do not have. I believe some of the advise you are getting would spin anyone's head. I can not bump a case shoulder, if I could I would shorten the case between the case head and case shoulder. to shorten the case from the shoulder to the case head the case body must be supported, meaning when I size a case the case body must be supported making it impossible to bump the shoulder without bumping the CASE BODY. Then there is that part about full length sizing, I can do that, but there is not 'sorta' or play like full length sizing, either it is full length sizing or it is partial full length sizing. I adjust the die off the shell holder to control the length of the case from the shoulder to the head of the case. There are some cases that require a gap of .014" gap between between the bottom of the die and top of the shell holder.

Redding does not have a competition shell holder with an additional .014" deck height, they have .010" maximum. then there is Skip's shims, same thing, sounds cool but to add a shim the die must be removed.

times, I believe it would help if you learned to measure the length of a case from the shoulder to the head of the case, remember, there are new/unfired cases, fired cases and cases that have been sized after firing. You need a comparator, it is possible , with a minimum amount of shop skill and knowledge to make a comparator.

F. Guffey

 

[fguffey]

I think what you say is your theories, cuz it does not match all situations.

Catshooter, true, I ask "How do you do that" and that makes those theorist mad!

They do a lot of memory work, like: The firing pin strikes the primer and the whole thing takes off in an attempt to out running the firing pin to prevent their little buddy the primer from being crushed etc., etc.. and I ask: "aren't you leaving a couple of events out". I have primers that never leave the bolt face, could be I have killer firing pins, that makes it impossible for the bullet, case and powder to out run the firing pin. Some of my shoulders on my cases are .125" from the shoulder of the chamber, no case head separation, no case stretch between the case head and case body, but still there is that cute little saying: "The firing pin strikes the primer then everything takes off for the front of the chamber until the shoulder of the case stops when it runs into the shoulder of the chamber etc., etc.., again, some of the shoulders on some of my cases in some of my chambers never have a chance to make it to the shoulder of the chamber because my firing pins crush the primer before it has a chance to take off with the case, bullet and powder.

If you have these problems, then solve them your way, but your way is not the only way.

Again true, I do not have those or anyone else's problem.

F. Guffey

 

[Bart B.]

Catshooter, what if someone loaded more than you, and for longer than you, and for virtually all commercial centerfire cartridges testing both hunting and match bullets in them for accuracy in both rail guns and all sorts of shoulder fired rifles then came to the conclusion that full length sizing produced better accuracy in all shooting systems than neck sizing when the dies were set up and used correctly?

I used to shoot matches with him. His successor did the same thing with the same stuff testing them the same way after he retired from his profession of doing that for the company that employed him.

 

[CatShooter]

Catshooter, what if someone loaded more than you, and for longer than you, and for virtually all commercial centerfire cartridges testing both hunting and match bullets in them for accuracy in both rail guns and all sorts of shoulder fired rifles then came to the conclusion that full length sizing produced better accuracy in all shooting systems than neck sizing when the dies were set up and used correctly?

I used to shoot matches with him. His successor did the same thing with the same stuff testing them the same way after he retired from his profession of doing that for the company that employed him.

In 2010, 2011, and 2012, I loaded over 18 tons of ammo - and I started loading in 1952/3-ish.

Love to meet your friend and swap stories.

 

[fguffey]

virtually all commercial centerfire cartridges testing both hunting and match bullets in them for accuracy in both rail guns and all sorts of shoulder fired rifles then came to the conclusion that full length sizing produced better accuracy in all shooting systems than neck sizing when the dies were set up and used correctly?

Bart B. And I ask: How do you do that? You are calming full length sizing and then you are calming "when the dies were set up and used correctly", is there more than one way to use a full length sizing die? Is there a way to use a full length sizing die incorrectly"

I size cases for short chambers, the easy one is .012" shorten than a minimum length sized/full length sized case, I size cases that are .002" longer than a field reject chamber, that is .016" longer than a minimum length/full length sized case and every length between .012" shorter than minimum length case to .016 longer than a minimum length/full length sized case. That is 28 different length cases when measured from the shoulder to the head of the case. catshooter could find it interesting talking to some one that likes to hear his own voice, I find it boring.

F. Guffey

 

[Bart B.]

Is there more than one way to use a full length sizing die?

Is there a way to use a full length sizing die incorrectly?

Yes.

 

[fguffey]

Bart B. And I ask: How do you do that?

You are calming full length sizing and then you are calming "when the dies were set up and used correctly",

To me that sounds like a CYA program, I can full length size a case, I can partially size a case, I can not full length and partial full length size a case. I can only partial neck size a case with a full length sizing die, if I size all of the neck with a full length sizing die I start sizing the case body before the complete neck is sized. Then there is the shoulder moving forward when the case body is sized down.

This reminds me of the world record shot by a magnum shooter with factory ammo. Readers were lead to believe the rifle was off the shelf run of the mill and the ammo was factory ammo. The deductive reasoning went something like: "Therefore full length sized factory ammo is better than the finest a bench rester can put together on the bench. THEN! everyone ran over to the other side with the pendulum with flawed information, the rifle used cost more than any 20 of my rifles.

F. Guffey

 

[mikecr]

There are atleast a few factors in FL sizing results:
1. Cartridge design
2. Load pressures
3. Sizing quality
Change any of these 3 and tables can turn

Also, many dies merchandised as FL dies are not at all. Some are bushing body dies, which are not FL dies.
I partial NS with Wilson bushings, and bump shoulders with Redding body dies(some custom). This is not FL sizing.
I get away with this because my cartridges are better(reloading-wise) than older designs, and my load pressures are below SAAMI max. And where I hold control, my chambers are tighter than SAAMI.
I also match brass by H20 capacity, which is not really possible with heavy FL sized brass(because of so much springback variance, and continual trimming away of brass).

When you're shooting something like a 308 or 30-06, you have no choice but to FL size because of case design. In these cases people can come to all kinds of conclusions, and delusions, about how their ammo shoots well, but it don't apply to MY cartridges.
I don't have to FL size to manage case dimensions/capacities/extraction, etc.
That's why I say FL sizing doesn't apply the same across the board.

 

[bigedp51]

The late Jim Hull of the Sierra ballistic lab and competitive shooter had a humorous saying about full length resizing.

"I get my best accuracy when the cartridge case fits the chamber like a rat turd in a violin case"

A full length resized case is supported by the bolt face and by the bullet in the chamber throat. The body of the cartridge case and the neck of the case do not contact the chamber and as long as the case has minimal runout it has very little influence on bullet alignment with the bore.

I'm with the rat turd in the violin case community because perfect cartridge cases with perfectly uniform case wall and neck thicknesses are few and far between. And for some strange reason Americans are buying cases made in Finland because of their quality.

Reloading: Partial Neck Sizing
The Shooter's Journal
Germán A. Salazar

"a full-length sized case in which the neck is also fully sized. There is clearance at the neck and in the body of the case, the closest fit anywhere is the bullet in the throat. If the neck to bullet concentricity is good (although it needn't be perfect), then the bullet will find good alignment in the throat and the case body and neck will have minimal influence. Let's not forget that the base of the case is supported by the bolt face or the extractor to a certain degree as well; this is yet another influence on alignment. As you can see, there are several points from base to bullet that can have an effect. My procedure is to minimize the influence of those that I can control, namely the case body and neck, and let the alignment be dictated by the fit of the bullet in the throat and to some extent by the bolt's support of the base. Barring a seriously out of square case head, I don't think the bolt can have a negative effect on alignment, only a slightly positive effect from minimizing "case droop" in the chamber. Given that a resized case will usually have a maximum of 0.001" diametrical clearance at the web, this isn't much of a factor anyway.

In conclusion, I believe that allowing the bullet to find a relatively stress-free alignment in the throat by full length sizing (including the neck) and turning necks to enhance concentricity gives the bullet the best probability of a well-aligned start into the rifling"

How many "perfect" cases out of 100 do you find?
And what will a warped banana shape case do to your accuracy with your neck sized only cases?