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Old August 22, 2013, 10:09 AM   #1
Magnum Wheel Man
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Neck sizing... where do you draw the line & go to full length ???

semi autos... yep I get that, but how about magnum pressures ??? any other conditions???

I've started buying a few neck sizing dies for my smaller bottlenecked cartridges... just curious if this is something I'll start doing for every rifle that has a camming action closing, or if cartridges like 338 Win Mag ( for example ) need to be full length sized ???

Contenders ??? probably full length size, as the cartridges have to be manually pushed into the chambers... or are the pressures low enough, that I could try neck sizing there ???
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Old August 22, 2013, 12:14 PM   #2
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If you are willing to feed them one at a time by hand, then you're good to go. But any gun I thought I might need to be able to get a fast follow-up shot with would be fed cartridges whose cases had been full-length resized.
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Old August 22, 2013, 01:18 PM   #3
Magnum Wheel Man
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so a bolt action box magazine wouldn't feed a neck sized case ??? I though most mags were not "that" close in tolerances ???
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Old August 22, 2013, 02:18 PM   #4
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even though I don't load rifle.....

I might, if I did, increase the sizing I do, and test.
And repeat.
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Old August 22, 2013, 02:54 PM   #5
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I wouldn't think a neck sized case would effect box fed bolt guns, only OAL would cause a problem with the round being to long.
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Old August 22, 2013, 06:27 PM   #6
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Magnum Wheel Man,

It's a matter of speed and ease of feed. I think rapid bolt work generally benefits from some of the same extra looseness in the case and chamber diameter fit that a self-loader does, though it may not be an issue with a case that has a pronounced taper, like a .30-30. I've not tried that particular round for speed feed.

Usually what happens with neck sizing is the case gradually becomes a tighter fit with each firing, and, depending how warm you load it, at some number of firings becomes tight, even for slow feeding, and has to be full-length resized again (at least enough to push the shoulder back a thousandth or two) and then started over on neck sizing. If you want reliable rapid feed, I would not be using fireformed brass unless I'd experimented with it carefully to prove it works well first. I would not trust it to continue to feed reliably at speed as it went through additional load cycles without additional testing.

For myself, for top accuracy loads I use a Lee Collet Die that I've modified a little (I should make a video of that process; all the world requires to be perfect is for time to stretch out a bit), followed by a Redding body die that bumps the shoulder back about a thousandth of an inch. This also narrows the case each time, but does not introduce needless case growth. Bart B. swears it produces even better accuracy than neck sizing alone will do, and awhile back I came around to thinking he's right. The case self-centers on the shoulder cone when you do this and if you are being careful to eliminate runout in your seating it results in a bullet that is essentially perfectly centered in the chamber neck when the pressure in the primer pocket pushes the primer back and sets and holds the shoulder firmly forward as the powder pressure builds. Such rounds also feed very nicely. It's as if every chamber were a match chamber.
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Old August 22, 2013, 08:00 PM   #7
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For accuracy, its best if everything is the same at each firing. The neck sized 223 case has 4% more volume than a Fl sized case that has been returned to factory specifications. Different case volume, different pressure, different accuracy. http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA456635 Summary

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Old August 23, 2013, 04:43 AM   #8
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Quote:
Originally Posted by 243winxb
For accuracy, its best if everything is the same at each firing. The neck sized 223 case has 4% more volume than a Fl sized case that has been returned to factory specifications. Different case volume, different pressure, different accuracy.
That is debatable. FL sized with the shoulder bumped back a few "K" is not enough to increase pressures. Also, once the primer ignites and the process begins, the case has expanded to fit and seal the chamber before the bullet starts to move. This would mean that both the Neck sized case and the FL sized case would have the same capacity when pressures peak.
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Old August 23, 2013, 08:24 AM   #9
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Quote:
I've started buying a few neck sizing dies for my smaller bottlenecked cartridges... just curious if this is something I'll start doing for every rifle that has a camming action closing, or if cartridges like 338 Win Mag ( for example ) need to be full length sized ???
Magnum cartridges do not necessarily use higher pressures than standard cartidges....338 Win. SAMMI pressure = 64,000. .270 Win SAMMI pressure = 65,000. So, it is logical that if one can neck size a .270 in a bolt gun(many do), and get it to chamber, one can also neck size a .338 Win. and get it to chamber.
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Old August 23, 2013, 08:51 AM   #10
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Unclenick posted
If you are willing to feed them one at a time by hand, then you're good to go. But any gun I thought I might need to be able to get a fast follow-up shot with would be fed cartridges whose cases had been full-length resized.


I fully concur. Autos are more reliable with "Undersized" ammo. The military learned this years ago. The military prefers reliability first followed buy accuracy.

Any gun can chamber more reliably with with FL sized ammo, but then what is your objective. Accuracy or reliability?

On the otherhand for precision shooting in other than autos, you would want to NSO.

Also to be considered is case life. As we all know, NSO extends case life significantly.
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Old August 23, 2013, 09:49 AM   #11
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I guess I didn't mention intention in my 1st post... I was initially just talking about my "everyday" bolt actions ( I'm currently in a phase that I take one of my bolt action guns out, & shoot targets on my range, in distances from 50 - 300 yards ) so in this instance, accuracy is more important that rapid fire... however I could see neck sizing transitioning over to some or all of my hunting bolt action rifles... I already understood that full length sizing is needed in most semi autos to insure full chambering ( hence my comment on "camming action" in my 1st posts ) but I guess the rotary bolt semi's do have some camming action as well, so maybe I should have said bolt actions ???

anyway thanks for pointing out the pressures of some of the magnums aren't any higher than some of the other cartridges... I guess I'll have to look at the pressures individually & look at the case shape & design on an individual basis as well...

NICK... I'd be interesting in understanding better the accuracy advantage of bumping the shoulder back a couple .001's... so... are you saying, that if the barrel throat is not completely concentric with the chamber, there is no way to insure that the case is inserted correctly each time, & having the shoulder back a couple .001's... how does that help ???
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Old August 23, 2013, 11:04 AM   #12
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Any gun can chamber more reliably with with FL sized ammo, but then what is your objective. Accuracy or reliability?
There is loads of debate on whether neck sizing only produces better accuracy, or if FL sizing with a small (.002" to .003") shoulder setback is what produces better accuracy.

I used to neck size only - but every 4th or so load, I had to FL size because even when firing in the same gun, the brass will still grow to where chambering was tight. And the last thing you want is to have a round that won't chamber when you need it to, whether hunting or at the range or in competition.

I switched over to FL sizing with a .003" setback and have seen absolutely zero degradation in accuracy, but also no longer have the worry of whether or not this round will chamber correctly.

Magnum - bumping the shoulder back .002" to .003" allows the round sufficient clearance to chamber without sticking, but also doesn't give the brass too much room to grow upon firing. Too much room and the case will prematurely fail. Too little and you may not be chambered correctly, or it may not chamber at all.

With a .002" or .003" clearance on the shoulder, it allows the round juuuuuusst enough room to self center as the firing pin pushes the round against the chamber shoulder (headspace). If you have a decent chamber and good loading techniques (low run out, neck turned brass, trimmed case), this increases the likely hood that your round is either perfectly centered, or as close to it as reasonably expected, before the powder burns. If you are starting off square, it only increases the chances of everything working as best as the components and machine will allow. And if you can repeat this between rounds, you get a much more predictable result.

Now - for an off the shelf hunting rifle with a production chamber, you likely aren't going to notice much difference in performance. Especially at hunting ranges (say 400 yards and under). But at longer ranges or with match chambers, these little things can make a huge difference in performance of your ammo or rifle.
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Old August 23, 2013, 12:26 PM   #13
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“I've started buying a few neck sizing dies for my smaller bottlenecked cartridges... “

I have neck sizer dies, I have lots of neck sizer dies, I also have forming dies, I have more forming dies than neck sizer dies, my opinion the forming die offers more advantages to the reloader than the neck sizer die.

Favorite die: My favorite reloading die is the ‘VERSATILE’ full length sizer die. I can size cases for short chambers, that would be .017” shorter than a go-gage length chamber, I can also size case to infinity, that would be a case that is longer than a field reject length chamber by many thousandths, IF! it can be understood my versatile full length sizer dies is used to size the case from the shoulder of the case to the head of the case. I think it worth of mentioning I size the cases in length that vary in length by .001” because my dies have threads and my press has threads, and, I can verify the adjustment.

Then there is the feeler gage, the companion tool to the press, there is never a reason to make wild guestmates in fraction degrees of a turn or converted to thousandths, I eliminate the middle piddle, I go straight to the verifier, the feeler gage.

I have never got the ‘hang’ of bumping, I have bump presses, I have presses that not bump, the most difficult thing I find about reloading is how a shoulder can be bumped without the neck and case body being bumped at the same time, I know, there is a bump die as meaning? bump the shoulder. and that is impossible, the shoulder can not be bumped without upsetting the case body, unless of course, the case body is being supported, and, that brings us back to “How do they do that, bump the shoulder, without case body support? I do not know, I use the versatile full length sizer die.

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Old August 23, 2013, 02:23 PM   #14
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I don't see how you can bump a shoulder without body support. That's often done by accident in chambering a round. You slam a round in real fast and if you extract the fired cartridge and measure the case, you find the shoulder has been set back a few thousandths, but the case body is now a thousandth or two wider as it has expanded into the chamber. That's what made room for the shoulder move without the force of a loading press or needing case lube to keep it from getting stuck.

The Redding body dies I use just are loose at the neck. Otherwise they are just the same as full length sizing dies. I set the should back a thousandth or two in one of these, then I trim and then size the neck separately with an inexpensive Lee Collet Die. I think setting the shoulder back by just a small amount is how the term "bumping the shoulder" was originally used, though I note that Forster has something called a Bump Die that I have not had an opportunity to try, so I don't know if it is doing anything truly differently. The guy who owns a Redding S FL die can use it as a body die just by leaving the neck bushing out of it. But that's an expensive die to use that way. May as well pull the expander and get the right size bushing and do both steps at once if you have one of those.


Magnum Wheel Man,

The main concern is that commercial chambers are often not exactly perfectly coaxial with the bore of the gun and bolt faces aren't always exactly perfectly square to the chamber. As a result, a case can come out slightly asymmetrical and then not fit back in the gun the same way until the case is rotated so the headstamp has the exact same orientation in the chamber that it did when it was fired the last time. In an extreme case, one fellow on the Shooter's Forum reported being unable to chamber some of his neck-sized-only cases at all. I suggested he try rotating the cartridges orientation in the chamber to see if he found a spot where it did fit, and he did that and it worked.

That's also a potential hazard for chambering from a magazine, and it also causes an accuracy issue in some chambers as the bullet is not cocked the same way in the chamber every time, even if you can squeeze the case in. Setting the neck back a couple thousandths and narrowing the case a little will both help the case fit and get the bullet in the neck the same way each time, whether the chamber's perfectly symmetrical and the bolt face perfectly square or not.
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Old August 23, 2013, 03:51 PM   #15
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I bought neck dies for everything I own. Reloaded both ways and feel you can get just a accurate with full length dies. Sold all my new neck dies.
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Old August 23, 2013, 04:16 PM   #16
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From the bushing dies you can if you remove the expanders and select the right bushings. The issue is about how sensitive your chamber is to bullet tilt. This video shows why.
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Old August 23, 2013, 06:17 PM   #17
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Does the full length die size the neck as well or do you still need to use a neck sizing die after the full length sizing die? My lee deluxe die set came with both and the directions arent very clear. It just lists them one after the other in order of operations. Doesnt specify either/or.
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Old August 23, 2013, 06:59 PM   #18
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ALL of my bolt guns are only necked sized and feeding issues are non existent. From 7mmBR to 7-08, 7mm mag, 6.5X55, 243 all were neck-sized and all had brass last for many reloads

Now, I do not have multiple guns in one cartridge designation - that would change things
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Old August 23, 2013, 07:28 PM   #19
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In some of the old competition cartridges I used for silhouette, I always neck sized and never had a problem. With the contenders in cartridges like 7tcu, we would even index them in the chamber, with no problems.
I sometimes doubt there is a big difference in accuracy with either method of sizing. I remember once reading an old Sierra manual where they clamed better accuracy was possible by full length sizing as the case would sit in the bottom of the chamber exactly the same every time, instead of fitting snugly in the chamber.
To each his own, but I don't think there is a definitive answer to which is better and the debate will probably continue forever.
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Old August 23, 2013, 07:33 PM   #20
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When I size my brass I full length size only. It takes a couple days to OCW and find the right bullet / powder and amount of powder but when it all works out you can make a jagged hole all day long. I don't think when you shoot a single hole a neck sizer won't help any at all. But the more items we buy the more money they make. I think alot of things are a marketing items. And we sometimes wanna believe we bought something that just brung us up to the next level. Lol
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Old August 24, 2013, 06:37 AM   #21
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“The Redding body dies I use just are loose at the neck. Otherwise they are just the same as full length sizing dies. I set the should back a thousandth or two in one of these, then I trim and then size the neck separately with an inexpensive Lee Collet Die. I think setting the shoulder back by just a small amount is how the term "bumping the shoulder" was originally used, though I note that Forster has something called a Bump Die that I have not had an opportunity to try, so I don't know if it is doing anything truly differently. The guy who owns a Redding S FL die can use it as a body die just by leaving the neck bushing out of it. But that's an expensive die to use that way. May as well pull the expander and get the right size bushing and do both steps at once if you have one of those”

Unclenick, Expensive die? No one measures the thickness of the bushing, both RCBS and Redding use the same bushings, then there are the bad habits, removing the bushing. With the bushing removed, the shoulder can not be sized, a small portion of the case is not sized at the shoulder/neck juncture. removing the bushing turns the expensive die into a do-nut making machine. I know, I have heard all the methods used to rid the case of the ‘dreaded do-nut’ when it is on the outside they push it in, when it is inside they push it out.

The expensive dies do not come with a bushing, bushings are ordered separately, I have the seating dies that come with the expensive sizing dies. The seating dies work.

Bump: It always escapes everyone's attention, I said I have bump presses and I have presses that do not bump, my non-bump presses lock-up, jam up or go into a bind, anything but bump. Bump and instructions: I have instructions that go back the the late 50s and early 60s, setting up a bump press is different than setting up a jam-up, lock-up ‘binder’ press.
If there was a reloader on this forum that uses an A2 RCBS press, by now, they would have shared some information on the use of the RCBS A2 press.

Bump and slamming cases into the chamber, I do that, I slam cases into the L.E. Wilson case gage with a drift and hammer while the case gage is setting on a block of lead. I also drive cases into the chamber with a drift and hammer. After that it depends on the receiver design, and, that little bit of thought that is absent when someone repeats the cute little saying: The trigger is pulled, the firing pin strikes the primer, and then the bullet, case, powder with the primer take off and rush to the front of the chamber at which time the case shoulder slams into the chamber shoulder and everything stops, then the bang and everything turns around and heads back the other way, but then there is a problem, the case locks onto the chamber leaving the case head to find its own way back to the bolt face.

I am the fan of cutting down on all that case travel, cut down on case travel by determining the amount of travel, I first determine the length of the chamber then form/size cases that off set the length of the chamber. I could purchase more dies, or I could trade up, I doubt die makers will improve on my dies, I can form short cases for short chambers by as much as .017” shorter than a go-gage length chamber and I can form cases to infinity or a more practical .014” linger than a minimum length case, that would be 26 different length cases in thousandths without grinding the bottom of a die and or top of the shell holder.

Redding competition shell holds cost #40.00 a set +/-. To get started I would need 5 sets, that is #200.00, I could say #240.00 but I have a #6 set I paid $5.00 for.

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Old August 24, 2013, 09:33 AM   #22
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No question Mr. Guffey is right that the chamber dimensions are key and they can be very individual. More specifically for neck sized case feed and function, the size of the chamber under pressure is key. As pressure grows, the action stretches. The brass has a smaller elastic range below its yield point than steel does, so the steel can stretch further than the brass is able to do and still spring back to shape. When there is enough pressure to stretch the steel enough to allow the brass to exceed its yield strain, when pressure drops again the steel returns to shape over top of an oversize case. This is what causes sticky bolt lift when a cartridge is loaded to the gun's individual limit.

But before the gun gets to that limit, everything inbetween can happen. If the pressure is very low relative to the gun's individual pressure limit, the case may keep springing back small enough to fit the chamber through quite a number of load cycles. These low pressure loads are the ones that will let you go on feeding and firing in many guns for a long time and still think everything is fine. Bring the pressure up a little higher, and the case may only pass its yield by a fraction of a thousandth at each firing cycle, so it winds up still fitting loosely for several cycles, but then finally reaches the size of the chamber and then starts to offer resistance closing the bolt. The inexperienced loader may think this means his pressure has increased, when all it is, is the need for one run through the full length sizing die before going back to neck sizing.

The strength of a particular action will determine the pressure thresholds at which it stretches enough for those brass expanding effects to happen. BigD says he's never had a feed failure with neck sizing, and that's perfectly possible. His pressures may be low enough or his guns rigid enough or his chosen brass brand elastic enough that it never does. If you don't use his guns and specific loads, though, all the other effects are possible and are often mentioned being observed. Again, this is individual to guns and load levels and even changing something like the brand of brass can easily alter the pressure at which symptoms happen (see this for one reason why the brass brand affects it). Federal rifle brass, in particular, is famous for stretching easily, giving pressure signs and sticky bolt lift at lower pressures than others.


Presence,

I hope some of the above answers your question. You normally use either the FL die to size the whole case down or the Collet Die for neck sizing only. Not both. The Deluxe die set gives you the choice, and if you use the Collet Die and load near full pressure, when the cases get tight you use the full length sizing die for one load cycle, then go back to the Collet Die. The Collet Die takes some experimentation to learn its feel, but it has three good features for the handloader:
  • You don't have to lube cases when you use it.
  • Because it sizes the neck over a mandrel, the dreaded interior donut at the neck and shoulder junction that Mr. Guffey mentioned can never form to pinch bullets.
  • Because it uses that mandrel to form the inside of the neck to a specific diameter rather than over-resizing the outside of the neck to a fixed diameter and then expanding the inside to final size, as standard dies do, it works the brass less, giving longer load life before needing annealing to prevent neck splits.
  • They produce low neck runout as the YouTube video demonstrates.

As to accuracy, it depends on the chamber. Below is a drawing of the result of indexing 8 rounds with 0.004" off-axis bullet tips at 90° intervals around the clock during 100 yard firing taken from test results obtained by Harold Vaughn and A. A. Abbatiello. The first gun is a benchrest gun in a machine rest. The tight chamber dimensions tend to straighten bullets out minimizing spread on the target due to bullet tilt. The second is the equivalent of an accurized military style Match Rifle (bolt rifle) using about the same degree of bullet tilt, but with no great ability to straighten the bullets out. Much of the bullet tilt is due to case neck runout. It is why the runout in the video I linked to matters. The Lee Collet die avoids it well because the mandrel approach avoids pulling necks off-axis as expanders are prone to.

We had a fellow on the forum, sometime in the last month, I think, who couldn't get groups below an moa until he switched to neck sizing with the Lee Collet Die, at which point they dropped to about half an moa. I don't know if that was because his cases needed to fill the chamber better or because he needed to eliminate neck runout. But either way, in his chamber with his bullets, the neck sizing method helped. Again, every chamber geometry will respond in it's own way.



Keep in mind sources of group error contribute their individual areas to a combined group. This means the diameters they add combine as the square root of the sum of their squares. The result is that an error source that opens a group from a bughole to a half an inch when it is the only source of error, will add only about an eighth of an inch to a group that is already at one inch due to other error sources. So, even if neck sizing or other factors you experiment with do make improvements that remove small group error sources, if the gun isn't shooting pretty tightly to begin with, the effect may be to show you very little or no obvious improvement. You might have to use Student's T-test or some other statistical tool to see if an improvement is really there, or if you are just seeing random changes in group size.

This group error addition problem causes a lot of people to conclude that one accuracy improvement technique or another does them no good because the improvement isn't gross. It might, in target shooting, actually cause them to pick up an occasional point or X, but they often don't bother to apply it long enough to find out. They also don't go on to systematical eliminate other sources of error to learn whether this particular improvement matters to their shooting or not.

Harold Vaughn wrote:
Quote:
"Now a lot of you will say that your rifle is capable of shooting more accurately than you are capable of shooting. Now I'll buy that, if you happen to be one of those people that just can't shoot because of flinching, or not being able to see well, or for some other reason. However, I can't agree with this for the majority of shooters, because I have fired thousands of rounds through accurate sporters on machine rests where the only skill involved is putting the cross hairs of a 20 power scope on the center of the target. Invariably, I get about the same accuracy when I, and other folks, shoot the same gun from the shoulder at prone position or from a bench rest."

Harold R. Vaughn, Rifle Accuracy Facts, Precision Shooting Inc. (R.I.P.), 2nd Edition, 2000, p.1.
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Old August 25, 2013, 09:17 PM   #23
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The most comprehensive test of neck only versus full length sizing fired bottleneck cases was made, in my opinion, back in the 1950's by Martin J. Hull; Sierra Bullets' ballistic tech. He resized all sorts of cases for use in all sorts of rifles; factory sporters, service rifles as well as match grade competition rifles. He got the most consistant accuracy using full length sized cases. Sierra still does that. They don't even work up loads for new lots of powder, primers, cases or bullet production lots. They use super accurate match-barreled rail guns to eliminate all human error possible.

His experiences have been shared with thousands; use a die that minimally sizes the case neck (die's neck diameter is about .002" smaller than a loaded round's neck diameter) and size the case such that the shoulder's set back about .002" and no more.

High power match rifles shot from 3 positions have used full length sized cases for decades for best accuracy. Benchresters have recently switched to full length sizing their fired cases. While their smallest groups are not any smaller, their largest ones are; by quite a bit. So, the over all accuracy is better; group average sizes are smaller. The accuracy you can count on is what the largest groups are.

Note best accuracy happens with bottleneck cases headspacing on their shoulder when the case neck is perfectly centered on the case shoulder. It's the case shoulder that centers the round's front end in the chamber, not the case body; it's driven hard into the chamber shoulder by the firing pin before the primer fires. Full length sizing dies better center case necks on case shoulders because the case body is held in alignment with the case neck when it's sized. Neck only sizing dies do not do that. If you think about this for a little bit, you'll realize that a .243 Win. round will perfectly center its neck and bullet in a .308 Win. chamber. As will a .25-06 round in a .30-06 chamber. With a huge amount of clearance around both the cartridge neck and bullet.

Sierra Bullets also learned than any crimping of their products in case mouths reduces their accuracy. It introduces another variable by increasing the release force spread needed to get a bullet out of the case and very, very slightly unbalances the bullet. They do not test any of their cannelured bullets for accuracy in crimped mouth cases; they know better. Neither does anyone else who's reached the best accuracy levels attainable.

Last edited by Bart B.; August 26, 2013 at 06:36 AM.
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Old August 25, 2013, 09:43 PM   #24
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Harold Vaughn wrote:
Quote:
Now a lot of you will say that your rifle is capable of shooting more accurately than you are capable of shooting. Now I'll buy that, if you happen to be one of those people that just can't shoot because of flinching, or not being able to see well, or for some other reason. However, I can't agree with this for the majority of shooters, because I have fired thousands of rounds through accurate sporters on machine rests where the only skill involved is putting the cross hairs of a 20 power scope on the center of the target. Invariably, I get about the same accuracy when I, and other folks, shoot the same gun from the shoulder at prone position or from a bench rest.
If that's true, it's truly remarkable. I don't know of any human that can hand hold a rifle so it's sights (and therefore the barrel's bore axis) are fixed on an aiming point like a machine rest does. They've got a heart pumping blood that moves muscles that move bones that moves hand held rifles. Through a scope and holding your breath, it looks like an electrocardiogram's waves mostly in elevation but with some in horizontal much like a figure 8.

Many Nat'l High Power Champs have tested their rifles and ammo from machine rests getting 1/3 MOA at 300, 1/2 MOA at 600 and 3/4 MOA at 1000 yards. None have shot them that accurate with the rifle shouldered in prone position. The best of them hold about 5/8 to 3/4 MOA because of pulse beat. Due to the tiny differences in holding from shot to shot, add another 1/4 MOA to where the rifle points when the bullet exits. Add these to a 1/2 MOA rifle+ammo accuracy and the shoulder-shooting accuracy is now about 1-1/2 MOA. Three times larger than the machine rested rifle and ammo produce. That's the group sizes they shoot at their typical best on bullseye targets. When everything is near perfect, they break records shooting 1 MOA groups off the shoulder with a rifle+ammo system that shoots 1/2 MOA by itself held perfectly still.

Good example's from 1971 when a friend tested his .308 at 600 yards with a machine rest. He got several 10-shot groups under 1/4 MOA. He won all three 600 yard 20-shot matches at that year's Nationals with perfect scores and high X counts. All three of his groups were 7 to 8 inches in the target's 12-inch 10-ring; about 1-1/3 MOA; 5 times larger than his test groups.

Some have used what's now F-class prone positions testing rifles and ammo with some sort of artificial support. 1/10 MOA holding areas are common. They can get 1/2 MOA 10-shot or 20-shot groups at the longer ranges with their stuff so tested, but never shoot that well in competition. Their holding area without artificial support's a lot bigger than with it.

Last edited by Bart B.; August 26, 2013 at 06:05 AM.
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Old August 26, 2013, 07:28 AM   #25
Magnum Wheel Man
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Join Date: July 26, 2006
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Thanks for the discussions guys... my thoughts on the neck sizers was to try to reduce percentages on the smaller cases, thus increasing accuracy... in the smaller cases, small percentages are greater... I am picking up a 17 Fireball, 22 Hornet, & 223 Remington neck sizer to start with... if I don't have good luck with them, I won't move up the scale any further...
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