Anyone who knows care to teach this ol' pup a new trick? For
years, I've done nothing but neck resizing cases. Seems like
there's been no problem with the need to bump the shoulders
back on any of my cartridges. I do have full length dies for
most calibers but haven't needed to use them. The thought was
always that neck sizing not only prolongs case life, but there
was better accuracy as well.

Now I'm reading that the BR pro's are using full length dies in
a manner that gives them more accuracy! Something about not
adjusting the die all the way down so the shoulder is not
bumped back? Could someone enlighten me of this relatively
"new" procedure? It apparently helps, or the BR guys wouldn't
be doing it.

If you are using a full length die, and you are adjusting the die to not bump the shoulder back, is that not neck sizing?

quote:

Originally posted by impala#03:
If you are using a full length die, and you are adjusting the die to not bump the shoulder back, is that not neck sizing?

No, that is "partial FL sizing" as depending on how far down you set the die to stop sizing, it may still be partially sizing the sides of the case.

I partially FL sized all of my bottleneck cases for many years. My procedure is simple: Adjust the FL size die for normal FL sizing. To partial FL size, just put a thin washer under the FL die. The thickness of the washer determines how "partial" the sizing is. My washer is 0.03" thick, and I made from the plastic lid of a margarine container.

Can't help you. Have been way from BR too long. Have you asked over on BR?

http://benchrest.com/forumdisp...Centerfire-Benchrest

I like to call it correct resizing:-)

You need a full-length sizerdie with proper locknut (ie-one that can be fixed in place-no Lee O-ring-style or similiar).

You also need your rifle, with the fireingpinassembly removed.

Install your die in the press, screw it in until it thouches the shellholder. Back it out 1 full turn and tighten your locknut (no need to bring out the cheater bar..)
Put a once lubed, fired case from your gun in the shellholder and size it.
Take the sized case and try to chamber it; the bolt will not close on this case (if it does you need to back the die further out).
Loosen the locknut, screw the die down a little more (1/4 of a turn or less), take a "new" case and repeat.
Once you reach the point where the bolts closes with a slight drag you have two choices-leave it like that or adjust just a little more to let the bolt close without any resistance.

Once happy; secure the locknut properly.
With a chamber and a diesett of correct dimensions one will very often end up with the die thouching the shellholder:-)

I always heard that you can't teach an old dog new tricks !

This one is particularly interesting to me because I am very curious and inquisitive. I spend inordinate amounts of time researching and have delved into the most scientific, physical corners of internal and external ballistics to such an extent, over many years, that I find I have forgotten half of everything.

Scientifically it gets very exotic. The multitudes of influences are really vast.

This matter of some innovative bench rest practice of full, or partial, resizing improving accuracy is still elusive to me. I haven't, as yet, found a plausible explanation that is supported by fact and science.

I read some reports. One curious shooter decided to prove to his satisfaction the rumor. He reported that in two calibers he achieved a 30% and a 35% improvement in accuracy, i.e. tighter groups by partial or full length resizing.

Conversely I read about a shooter that couldn't get his rifle to shoot well after spending hundreds of dollars re-crowning, lapping, glass bedding, installing new triggers and more.

The thing that is most consistent about ballistics is it's inconsistency. Full length resizing may work for some but not for others.

When contemplating, and debating, the effects of partial vs full length resizing and bumping the shoulder, remember that the case is TAPERED. At least with my dies I can partially resize and reduce the case diameter or full length resize reducing more due to the taper.

I think the jury may still be out on this bench rest reporting. Some of it may be just blarney and some may be steeped in fact. Probably each individual who wants to know will have to prove it to themselves by actually shooting loads. In the meantime I can't think of any detrimental aspects to full length resizing vis a vis accuracy. As to shortening case life, reworking the brass by sizing is minor compared to excessive loads that stress the brass. There are reports of 20 - 30 reloads in some instances.

My preference is to full length resize both for accuracy and in ease of chambering hunting loads. The loss of a few cases due to premature failure is economically chump change.

My advice to the "old Pup" is to full length resize like the Bench Rester's do. You can go to bed at night and sleep comfortably with the knowledge that you are up to speed with the latest, covering all bases.

I neck size (Redding competition dies) in .222 Rem and .308 Win for my target rifles (with an occasional shoulder bump into a body die when chambering becomes noticeable). For all other hunting/shooting calibers (9,3x74R, 9,3x62, .300 Win, .30--06, 7x64, 7,5x55), I partial size with regular dies. It means that, by cut and try chambering, I screw in the FL dies until it sizes the neck and just kisses the shoulder without pushing it back. I stop when I "feel", oh so lightly, the bolt closing. It's as close as you can get to true neck sizing, respecting chamber dimension and insuring case life. Ideally,one should remove springs, extractor and firing pin from the bolt so as to avoid every interference from dito (I don't however, being too lazy).

That's the way I do it too Andre depending on what type of rifle I am loading for. If loading for single shots, I barely bump back the shoulder. The single shot does not have the camming power of the bolt action.

While we're on the subject, I'll differentiate my approach to partial and neck sizing a tad further.

In true neck sizing, I opted for Redding NS-die with bushings and select the latter according to (variable brass thickness) cases collets. I start from the outside neck diameter of a loaded round and substract .001" (turned necks) or .002" with unturned brass.

When partial sizing with a standard FL sizer dies, I either kiss the shoulder or stop just before, letting the individual rifle decide. Anecdotically, my FN double rifle in 9,3x74R shortened brass life (mostly Norma of wich I am amply supplied) to 2-3 firings, at most, before displaying incipient separation warnings. True the '74R has a rimmed case with a nearly unnoticeable shoulder and those rifles being largely handmade, reproducing identical internal dimensions in 2 separate barrels isn't that evident (in practice, no one cares anyway as these guns are pure hunting rifles and only a few idiots like me would care to handload for them, let alone pick up the ejected fired brass). Well this idiot found a solution via partial sizing. The procedure remains as described above up to a point. As soon as headspace has been adjusted from rim to shoulder on one barrel, it won't necessariy fit the second barrel (don't even think about forcing the rifle close as you may damage the hinge pin and bring the rifle off face !). The solution lies in finding an intermediate sizing portion of the case (by cut and try) until you obtain a resized case that drops freely in each chamber and allows the action to close easily, with the unmistakable sound of a bank vault.

I'll admit this is not 100% perfect as headspace in only partially adjusted but, nowadays, I can reload my 9,3 brass 3-4 times without having it develop an internal separation groove (cases might and would probably last longer but, considering my generous supply of 1x fired cases, I see no point in pulling the tiger's tail...).

quote:

Statistics for the last 30 days

Andr'e:

As a very meticulous old XXXx I just love this in depth analysis. Gracias, Merci! Thanks!

You are making a very strong case for my philosophy that full length resizing is the overall, best practice as opposed to half way measures of partial kissing, neck sizing and other off color whatever.

I'm open to comment and wanting to learn. Can/will anyone present me with any information that is detrimental to accuracy by full length resizing?

Further can anyone give me some plausible explanation wherein full length resizing shortens case life.

Its not "new" my friend, its as old as dirt..your neck sizing with full length dies..

Here is the formula: Blacken your case neck and shoulder and that will tell you how far down the neck your sizing..I usually back off a turn or two and start from there, trying the case in the rifle chamber as I go until I get a light crush fit, then set it back about a half turn to be safe on feeding..

All that said I full length resize all my hunting rounds, putting feed and function ahead of accuracy and case life, the difference in accuracy and case life is very little, if any in my tests. If you do the tests yourself, and forget the written page, which mostly is repeated pass ons from some gun rag article that is being passed on as fact as opposed to practical try's and by goshes, you will probably arrive at the same conclusion if your a practical person. and not plumb et up with technicalities as some reloaders and gun nuts tend to be.

I believe you may be right about most part of sophisticated case prep' and precision loading. Formerly, I used to neck turn all cases, reform primer pockets, deburr primer vents on the inside, check case neck concentricity, segregate cases by weight, weight each powder charge, etc. (NB : including my hunting ammo).

One day, with hunting rifles of proven sub MOA accuracy, I compared groups shot with fully prepped cases vs. groups with 1x fired cases with no special preparation + thrown charges (with a Harrell's measure, that is). For the second part of my test, I even mixed up both batches.

I hate to admit that I had to work hard to find a difference, if any. However, I'd like to think partial sizing and weighted charges showed a slight superiority (I still believe it's best to stay close to chamber specs and true NS should prove its worth in match rifles).

Since, I no longer neck turn and insist on neck concentricity of my hunting ammo but go on with the other operations. I now know it's all mostly in the head but it gives me confidence at the moment of pressing the triggger...

Thank-you to all. My original reason for asking is that my favorite die company,
Forster, does not offer a neck die in their BR die sets in .204 Ruger. They do have
a bushing die but for me, that's cost prohibitive. So I got the die set with the
full length die, and had heard of this partial sizing process. You all have
explained it very well. Thank-you again.

Partial sizing FL sizing has been around forever.

If you really want to learn a new trick, get a set of Redding Competition shell-holders. They come in a set starting at standard height, and move up from .002 through .010" thicker in .002" increments. With a set you will easily be accomplishing what handloaders have been trying to do by backing off their dies a bit. With the die not touching the shell-holder you are at the mercy of press flex.

Dogleg is right. Done correctly in a heavy "O" press, both ways are equal in results but the Redding competition shell holders collection just make things more straight away and are to be prefered with a "C" press.

/The only thing to keep in mind is whey concocting reloads for hunting, especially Dangerous Game, always full length resize cases.

For varmints, target and especially competition BR , neck sizing, and all the stuff that goes with it is a good idea as a silly millimeter can make a win or loss..

I have seen way too many times a stuck case and a magazine full of powder and bullets stuck in the lands and our clients crying and cuss'en because there ever so carefull handloads caused them to miss a trophy or in one instance the client was tell me and the PH to kill it as it had us located... the PH's double rifle jammed with a bullet stuck in the chamber. I got to kill the buffalo, does it get any better than that!

quote:

neck sizing, and all the stuff that goes with it is a good idea as a silly millimeter can make a win or loss..

I've already confessed above : I know it's all in the head but it instills confidence the moment I press the trigger...

quote:

Now I'm reading that the BR pro's are using full length dies in
a manner that gives them more accuracy! Something about not
adjusting the die all the way down so the shoulder is not
bumped back? Could someone enlighten me of this relatively
"new" procedure? It apparently helps, or the BR guys wouldn't
be doing it.

I am not a bench rest shooter, don’t attend the matches. Some bench rest ideas are useful for what I do, others are a waste of time. Where are your priorities? Is feed and extraction the most important considerations , or do you want accuracy, and don’t care if you have to use a cleaning rod to extract your cases from the chamber?

I shoot HM scores with full length resized cases in Across the Course, mid range, not unfortunately at 1000 yards. I set the shoulder back about 0.003”. I use small base dies whenever I can find them. My accuracy is very acceptable. People find that neck sized cases or partially neck sized cases don’t necessarily extract when desired. In matches, you shoot against time, and conditions change with time. If by neck sizing only you convert your breech loader into a pseudo muzzle loader, you burn time knocking the case out from the muzzle, you will ruin your position (if you are a sling shooter you appreciate the importance of staying in position) and the conditions will have changed between shots. The wind seldom blows the same all the time. I don’t know any good shooters who don’t full length size cases, but full length sized cases provide match winning accuracy, and the best feed and extraction characteristics obtainable.

Just PFL'ed some Whelen cases this morning. Had 1x fired cases from a different rifle, but they chambered easily in my new rifle. Set the FL die at a point backed out 1.5 turns from touching the shellholder. This sized approx. 1 caliber length of the neck. Worked like a champ.

The bench rester's are a special group of shooters whose goal is/are very meticulous, and while seemingly compatible with the rough and tumble "hunter's the two types have some differences in operating.

While I do not disparage my fellow bench rest shooter I will say that case preparation for hunting is a lot less demanding.

We can do whatever we want to with impunity so long as it is within the guidelines of safety.

If I had to choose one or the other, I would buy the FL die, and do partial full length sizing. As a matter of fact, I have operated like that for a very long time.

For a few of my cartridges (25-06, .22 Hornet, 30-06) I also have the collet die for neck sizing. I use them both.

Neck sizing new brass is nice. After they have been fired a few times using neck sizing, the cases begin to get snug in the chamber. I then do a partial FL resize on them, and they are good to go with neck sizing again for a few more times.

The only thing I had to address with this method, is getting the collet die mandrel to replicate the same neck tension of the FL sizing button. This is easy enough, and once it is done, it's done.

In .308 Win and .222 Rem, I use Redding competition dies with a neck sizer and bushings. I also added their body die. When chambering becomes a little tighter, I use the latter to lightly bump the shoulder, leaving the rest of the case untouched, i.e. to chamber dimensions. However, this is only meaningful when looking for extreme accuracy in match rifles. I doubt if hunting rifles would benefit from it.