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6 br accuracy

John,
LIke Boyd said. Bench shooters are F/L sizing, But it is a shoulder bump only. For the very best in the 6BR use a Harrel F/L bushing die. You send him fired cases and he will get you a die to match your chamber. Adjust the for a 0.002" bump on the shoulder. A peice comes with die for measuring. All this can be done with other die. At the start neck will work and be accurate, but then the case will become tight, going in ( tight because in length) or tight coimg out ( the snap at the end of bolt lift due to being tight in the butt). when the cases get tight the rounds will be out of the group.

For your answer neck is more accurate, but when one case gets tight, it is not going to be as accurate. You want know it is tight until you chamber it in a match, then it is too late.

Mark Schronce
 
dmoran said:
CatShooter said:
... but if easy feeding were not a consideration, and raw accuracy is the only consideration, then neck sizing is the hands down the winner - not to mention very long case life.

"Crush is your friend" ;)


That is a totally biased statement and in no way the truth....

As to "Crush is your friend".... it is risky and can be very dangerous, that has extreme limitations for success.
Inconsistent pressure and spiked pressure is the inherited risk of crush fits.
And is some of the worse advise I've yet to see.....


To those of you who wonder why I don't post here no more... it is statements like this, by indicative keyboarders, that reply's [sic] with a corruption of truth, for some self serving motivation only.

Donovan

Donovan.. your comments make no sense.

First, how are they "biased"?? Biased in what way? Biased means that someone has a vested interest in one side of an issue - (like I sold neck sizing dies, so I was biased against FL dies), and that effects what I am saying, but I have no vested interest - I don't make or sell neck sizing dies, so I can have no bias.

Plus, saying ".... it is risky and can be very dangerous, that has extreme limitations for success. Inconsistent pressure and spiked pressure is the inherited risk of crush fits." is so silly that it is beyond description - why?... Because all, or almost all, bench shooters use crush!

The standing instructions for setting a FL die are to remove the ejector and extractor, and set the FL die so the bolt handle will fall approximately 1/3 to 1/2 way down and come to a stop before completely closing on the FL sized case. Why does the bolt handle come to a stop half way down, Donovan??

Because the case shoulder has hit the chamber shoulder - and that is because the case is longer than the chamber by several thou... then when you close the bolt completely, you compress, or "crush" the case by several thou. You do it, and most (if not all) successful bench shooters do it... yet you claim that it is "... it is risky and can be very dangerous, that has extreme limitations for success. Inconsistent pressure and spiked pressure is the inherited risk of crush fits."

Just exactly, how is it dangerous? How does it have any effect on the pressure at all, since you do it, and most everyone else does it, and no one is blowing up... they are shooting tiny groups, when they close their bolt on a case that is several thou longer than the chamber.

The length of the case, when longer than the chamber has absolutely no effect on pressure, since it does not effect anything in the pressure making part of the system.

You need to think before you rant... you do the very thing you are ranting against. I just do it on purpose, and by a few more thou. My bolt stops close to the top, and yours stops half way down. A few thou difference.

--------------------------------------------------------------------------------------------------------------


ewspears said:
catshooter,

You Said: "... but if easy feeding were not a consideration, and raw accuracy is the only consideration, then neck sizing is the hands down the winner - not to mention very long case life."

If You limit that statement to only include store bought Redding and RCBS Dies then I agree!

But I need to inform you that the best benchrest shooters for the most part buy a resize reamer that is a perfect setup for there chamber reamer (doesn't re size brass anymore than necessary to allow smooth bolt closure)
They then make there own FL resizing die from a newlon blank, get it heat treated-hardened, and then polish out the .0003" to .0005" it shrinks in heat treatment.
This results in a die/chamber setup that will maintain .0002" neck concentricity which is not possible in any of the following:
1) Any Die that uses a floating Bushing for Necksize
2) Any die that pulls a sizing button thru the neck I.D.

I need to clarify my statement; When I speak of benchrest shooters I was talking about 100 & 200yd. NBRSA or IBS Competition. Shooting 6PPC, 30PPC, & 30BR!

This so out of context that it requires no reply - it is silliness to an extreme.


-------------------------------------


What is really sad is... that all of you missed the main part of what I said - it was about us making rules with a quick "committee's" discussion without thought of the unintended consequences down the road.

We make a rule change about the weight, and the best design scopes disappear, and are replaced by poor substitutes. I have heard hundreds of shooters complain about unreliable elevation and windage tracking in modern BR scopes - I have NEVER heard one complaint about unreliable tracking with a Unertl or Targetspot.

Mitchel tried to get an external adjusting scope to market, but apparently, he retired and no one had what it took to keep it going. Some very knowledgeable folks are freezing the internal adjustments of modern scopes and making external mounts for them.

So we lost a valuable asset, and now we try to reinvent the wheel, so to speak.

Did we do good???
 
A long time back, when internal adjustment scopes designed for benchrest were new, a fellow who was very experienced and accomplished in benchrest mounted one of each on his rail gun, and after shooting the rail for a bit, and looking at where the scopes were at the end, he tool the slider off. I can't think of any fellows that have or currently use sliders that could keep up in a modern benchrest match that was not for unlimited class rifles, even if allowance was made for the extra weight of their scope, and in unlimited there is not reason, that someone could not use one if he wanted to, for that matter it could be done in heavy varmint without a problem. Three pounds difference plus the weight of an internal adjustment scope is enough. The truth is that accuracy standards have increased over time. If you don't believe me, look at the aggregates reported in match results over time. (which tell a lot more than individual groups), and go back and reread all of those magazine articles that got all excited about MOA accuracy from factory rifles. The optics of some of those old scopes were superb but resetting them after every shot is a process that is not as precise as the best internal adjustment scopes.
 
Boyd...

All the ones I had at the time, and all that I saw, including the Remington, had return to battery springs.
 
I have a question and please forgive my ignorance Cat. From what you seem to be describing, you are using the chamber of the rifle itself as your FL die....Is that right?

Thanks
 
22BRGUY said:
I have a question and please forgive my ignorance Cat. From what you seem to be describing, you are using the chamber of the rifle itself as your FL die....Is that right?

Thanks

No... not right.

Anyone that properly sets a "bump die" winds up with a case that is a little bit longer than the chamber - to use the chamber as a FL die, the case would have to get shorter... id est, if you measured a case, chambered it, and then extracted it, it would need to be shorter - but we all know that brass has a fair amount of spring.

So the bit of crush (or whatever you want to call it), just holds the case firmly in place in the chamber cone.

It is no big deal - we all do it, we just don't describe it the same way.
 
I would challenge anyone to shoot as well as the current crop of top benchrest shooters do before he says that what they do results in less accuracy than what he does. That would require going to some matches and shooting. The other thing, there basically two benchrest tactics that may be used exclusively for a particular match, or in combination, running, and picking. The current 100 yard five shot record, for a 10.5# rifle is .0077". The fellow that shot it determined after his first shot that because the first shot did not go where it should have, that he needed to hold off for the remaining four. Because short range shooters can see their bullet holes as they make them, they often build groups one shot at a time, and since it is often true that the wind does not hold for the length of time that it takes to fire the entire group it is the usual practice to use the sighter target, mid group to refigure hold off for a different condition. There is also the practice of holding off based on experience rather than referring to the sighter target, a risky business. None of this qualifies as waiting for a lull in the wind and rattling five down range. On the other hand, good shooters have done well with loads that were mild enough to get away with neck sizing. To properly understand what this entails, you need to know that perhaps 15 or 20 cases are used for a whole weekend of shooting which would usually entail 100 record shots and perhaps 2/3 that number or more of fouling and sighter shots, while continuing to have a light enough bolt close to not interfere with quick shooting when needed. Even when one is picking, there will be situations where a shooter will need to shoot in a different condition, because of time constraints and use the sighter target to to determine the required hold off. In these instances, it is necessary to be able to fire load and fire again quickly enough so that the condition that the sighter shot was taken in is the same as the following record shot. Shooters who do not routinely shoot behind a row of four flags at 100 yards or five to six at 200 will undoubtedly fail to have a full understanding of what I am talking about because their understanding of the wind is based on much more simplified and less complete information, but I invite anyone to come to a sanctioned benchrest match and spend some time observing the flags. If you have time, go to You tube and search for Tony Boyer, and watch all the videos. He has the most hall of fame points of anyone in short range benchrest, by a wide margin, and while you are watching him shoot keep an eye on the flags, and take note if he waits for a lull and then shoots all five shots. Some of the shots that you will see are taken on the sighter, so you may want to watch a video more than once to see when he starts on the record target, and in at least one case, it is probably the first group of the morning or afternoon, and he takes more than one load to the line, and use the shape of the group on the sighter to choose what he will use on the record target.
 
Catshooter, Mark Schronce has supported here what both you and I have said on the subject of sizing.
That not every BR shooter FL sizes, and IMO, that it merely takes a plan to do otherwise.
Without this plan, then cases eventually get tight. Not a problem if they're all exactly that way, except it doesn't suit the needs of machine-gunning rounds.

Shoulder bumping only, with partial neck sizing, is in no way FL sizing.
You get there to begin with correct fitting dies, and it damn sure helps to match chambers and dies with pre-culled brass in-hand.
You don't size that new brass to some arbitrary dimensions with dies, you size it with your chamber, and maintain this planned fit with your dies.
It's already known that this is too much to mange in point blank BR. That the competitive underbore cartridges there rely on extreme pressures from fast powders behind light flat base bullets from short/stiff barrels. And extreme pressures carry a price that takes them back to FL sizing.
Well PB BR is a speck in the shooting community.
It doesn't represent well what the rest of us do or should do. For instance, none of that plan is viable to a 6br or 6xc and ~105gr boat tails, where barrels are longer and slower powders are used. Accuracy here is NOT based on a pressure peak work-around.

A 6Dasher with it's 40deg shoulders and low body taper can be made to shoot as well(for LR), and better in the long haul, without ever FL sizing. Just bumps(minimal) and partial neck sizing.
And same with a 260AI, or an improved 7SAUM, etc.
When you do no more than this, you trim less, you stop creating bananas out of your cases, your case heads stay straight, you stop forming donuts, neck tension is stable, primer pockets stay tight, the webs don't thin, your case capacity and load density holds.
If you match H20 capacity on these dimensionally stable cases, ES improves. If you tune your neck tension, on necks that don't change, your tune improves. If you set the correct clearances in YOUR reamer, the necks will not change in hardness, and you will never need annealing. And the webs will not grow to form clicking extraction, as they will never yield, but stay within springback.
Viability in this comes down to case design and load pressures -vs- barrel steel around a given chamber area. All are choices and included in a plan.
 
My point was not that neck sizing is less accurate than FL but that it is not more accurate, and that most shooters who read this have absolutely no experience with a FL die that truly fits their chamber. The Harrells dies that are in common use, are FL dies that do more than bump shoulders, but they move so little brass that cases are definitely not made banana shaped by their use. As an aside, I have an ordinary Hornady one piece 6PPC die that has a neck ID that seems to be .258 (which makes it ineligible for use with my .262 neck chamber when using 133). It sizes cases from my chamber less than .001 at the back, and more than I would like, (.0025 at the shoulder). Cases from this die routinely measure a half to a third of a thousandth total indicated runout at the case mouth. I am looking forward to doing more work with the new LT 32 since it does not seem to need the neck tension that 133 prefers and that would allow me to use this die. The one downside is that I will have to do a little more trimming. The best way to determine how to size your cases is by actual testing, but I would suggest that conclusions reached using typical ill fitting dies are not universal, but only reflect that particular die's lack of fit with the chamber that it has been paired with. When all is said and done, it should be your targets that determine what procedure that you choose.
 
You can lead a cat to water, but cannot make him drink.

It is obvious to me that Boyd, Donovan and MarkS as well as myself have shared the firing line with the absolute top shooters in the country.

The members here should watch out who they listen to as anyone can type and lead the choir in the wrong direction.

Boyd nailed it when he stated the brass work hardens at different rates and you will have very inconsistent bolt close pressure with neck sizing.

I would never go to all the trouble I go to to prepare for a match if there was a better way.

That way is partial FL sizing to get .0015"bump of the shoulder. This is not possible with neck sizing.
 
Yup... you get it.

Some people don't believe there is a world past 100/200 yd bench shooting.

:)
 
BoydAllen said:
.. If it works for you, that is all that is required. The other issue is that very few shooters have had any experience with dies that are custom fit to a chamber, and as a result, the experience that they have had with off the shelf dies prejudices them against FL sizing. For the dies that they have used, their conclusions are valid, but those experiences should not be taken for universal truths....better dies...different truth.

I'm a big fan of Boyd Allen.
 
Lapua40X said:
BoydAllen said:
.. If it works for you, that is all that is required. The other issue is that very few shooters have had any experience with dies that are custom fit to a chamber, and as a result, the experience that they have had with off the shelf dies prejudices them against FL sizing. For the dies that they have used, their conclusions are valid, but those experiences should not be taken for universal truths....better dies...different truth.

I'm a big fan of Boyd Allen.

+1

Donovan shoots 1000, MarkS has achieved world records at 600, my game also is 600 yd IBS and was one of 4 shooters who agged under 2.4"for the first time ever at an 8 target event, last September at the IBS 600 yd Nationals. The others names you might recognize more than myself. Richard Shatz, Mike Hanes, Samuel Hall.
 
Like the man said if you did it, it ain't bragging ..... but full length is the only way to go, i want the same size case every time. Neck sizing and shoulder bumping a non supported case is a joke, some are living in the past. I size a Dasher the same as i sized the PPC in the mid 90's with a FL die and guess what The Dasher now shoots as good as the PPC did then... in the mid zero's @ 100 yds. with 103 Gr. bullet........ jim
 
I've found if the brass is a little long in the shoulders accuracy remains. If it gets tight at the web all hell breaks loose. Just what I personally experienced. Since then my neck sizers and homemade shoulder bumpers gather dust.
Fl sizing gets a bad rap because too many shooters followed the simple instructions that came with the dies.
 
A little tight brass story:
When I first started shooting short range matches, I did not realize that as the brass was reloaded a number of times over a match weekend it work hardens and requires a slight die adjustment to maintain shoulder bump. By Sunday afternoon I had an entire loading block full of brass that was too long at the shoulder despite having been full length sized at the same setting that had worked Saturday morning. We were shooting a match at 200 when I thought I saw an opening to run my shots, and I got busy, working the bolt while holding the rifle mid action from the bottom, with my loading hand. There was nothing smooth or fluid about it. I was palming the bolt open with and upturned open hand, and cycling it always turning my open palm in the direction of desired motion. I must have looked like some sort of mad thrasher to the meticulous older shooter next to me, judging from the look that he gave me, but it worked. I won the match (rare occurrence, individual group, not agg or grand or two gun) running the group as fast as I could, ignoring the rest controls and manhandling the rifle back on target, glancing at the flags and pulling the trigger. The key was that all of the cases were equally tight. It is a good thing that I grease my lugs fairly often. Sometimes even a blind squirrel finds an acorn.
 
Boyd, I remember when they threw out the brass at the end of the match, nobody full length resized. Now you can get a custom die under a 100.00, how times change. You can wear out a barrel with 20 cases...... jim
 
now, let's see...oh yea, "6 BR accuracy". Tsingleton...my 27 inch kreiger, 14 tw shot some berger columns with LT 32 29.6 gr at 3540 fps and printed a 3 shot hole of .084 in. i seat .020 into the lands and used russian primers, all of which give a microsec hangfire. i know russians are quite hard. i uniform pockets and seat to the max and they still click/bang and i mean "a microsec" apart. the cci 450 don't but i have a LOT of the russians. both guns are shooting small holes and i'll check loads for the 62 euwins and 65 WEBS and post tomorow.
 

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