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Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/22/2009 at 04:13
8shots View Drop Down
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After owning a rifle of which the chamber had een cut skew, I have come to the following conclusions on bullet runout and concentricity gauges.
My conclusions are further based on a new barrel with a chamber cut straight.
 
The runout on a bullet is caused through a skew chamber and not improper loading methods, dies or presses. And I am not talking of presses, dies and the like that is broken, bent twisted or in other ways and means stuffed. I am talking of normal good quality reloading equipment in good condition.
 
I say this because I have used the best benchrest dies money can buy and used shells from a skew chamber. The runout was still in excess of 4th or more. In other words dies cannot fix runout.
 
The same dies, using shells from the now straight chamber are producing runout of less then 1/2thou.
 
A runout gauge can assist you to determine the straightness of your chamber by checking for runout. It has very little other use. In other words once your setup (rifle or reloading system) produces either a lot of runout or little runout, then not much else can be done. So my runout guage at $140 was a rather expensive item sitting on the reloading shelf.
 
I know some guys use their runout gauges to sort bullets into piles of say 1th, 2th, 3th runout. But is this a practical use.
I am currently only producing less then 1 thou runout bullets.
 
Anyone else with similiar thoughts or do I have the wrong end of the stick?
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/22/2009 at 10:03
Texas View Drop Down
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Howdy 8shots!
 
Run-out is a topic near and dear to my heart, as I have struggled with this reloading "parameter of interest" off and on for, oh, 20-odd years. I must say that you are doing very well in your reloading efforts since you are consistently achieving less than 0.0005" runout on your handloads. I have reached that point (<0.0005") in my runout reduction campaign also, but I have found that what you posit at the end of your post is not necessarily always so. In the case of reloading fireformed brass, I agree that the chambering quality of the rifle makes a great difference in what runout the handloader can achieve and that it is almost impossible to correct "tweaked" brass that comes out of a gun that has a poorly cut chamber.
 
However (you knew it was coming...), in the case of loading both new brass as well as fireformed brass from a properly chambered rifle, I have found that quality dies and equipment and proper technique do make a great difference in minimizing the runout measured in the finished handload. My experience is that it is entirely possible to make nonconcentric and bent (BIG runout numbers) handloaded ammunition from almost perfect fireformed brass. Same thing holds true with new brass, although it doesn't usually start out all that straight before it is fireformed in my experience. For me the Redding bushing neck die and body resizing die, and the competition bullet seating die were the tools that have allowed me to get to the point I have reached now, as I just could not seem to find a set of "traditional" threaded press dies that would get the runout numbers I wanted. But that is me, YMMV. I also don't worry too much about new brass any more, either, as I can't find the accuracy I want until the brass is fireformed. And in a factory-barrelled and chambered rifle, runout may or may not be a concern anyway - one must have a rifle that is at least "so" accurate to even detect the effect of good or bad runout numbers.
 
But no worries, 8shots. All I am really saying is that I do not think the monies spent on run-out gaging instruments to be wasted! I know from my own experiments that minimizing runout will make a big difference in getting to the next level of accuracy, and if one is not measuring runout then one certainly is not controlling or minimizing runout. I also have found my gage to be useful in evaluating the quality of factory-loaded ammunition - but I warn all readers, do not go here unless you have a strong stomach! I have found very little factory ammunition that measures acceptably well for runout. And this includes some very pricey "_ _ _ _ _ _ Custom Trophy-Grade" ammo I purchased when I had a hunt pop up for which I had no time to load ammo.
 
I hope you all don't find this too boring! Ha! Ha!
 
Regards,
 
Texas
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/22/2009 at 10:13
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I'm glad you posted that. It made me realize that when dealing with Rem rifles that have accuracy issues there is need to check chamber alignment. Something that I have taken for granted because of "assumed" Rem quality. Your experience proved that was to be questioned. I was also suprised to see how irresponsible Rem was in customer service. Especially suggesting that yours was within accepted tollerances. As bad as that experience was it brought alot of valuable info to light. Keep us up on your progress.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/22/2009 at 19:50
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Excessive bullet run-out can be caused by a bunch of stuff, including brass, dies, chambers, etc. To blame it on only one cause is simply wrong. It can even be caused by the bullets themselves. I am convinced that the reason many handloader believe boattailed bullets are more accurate is because the boattail often allows them to be seated straighter in standard dies.

Years ago a well-known reloading die company made many of their dies by first reaming the body of the case, then using a separate neck reamer. An example would be .243, .308 and .358 Winchester dies. Very often the neck of the full-length die would be out of alignment with the body portion of the die. This almost guaranteed extreme bullet run-out and hence inaccuracy. I know this because I owned at least two sets of such dies, and after I figured out what was going on and bought another brand of dies the runout problems went away. And the problem would have been hard to diagnose without a run-out gauge.

In fact I would say a run-out gauge is one of the essential tools of the serious handloader.

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/22/2009 at 20:46
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Hey 8shots, drop the stick, pick it up by the other end.  Wink
 
Of course, the concentricity of the chamber can easily be determined by checking the neck of the brass after firing the case. 
 
Are you checking concentricity on the bullet ogive or the case neck?
 
What dies are you using?
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/23/2009 at 08:06
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"The runout on a bullet is caused through a skew chamber and not improper loading methods, dies or presses"
 
It seems your experience dealing with run-out is somewhat limited.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/23/2009 at 09:44
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When your bullets runout it's time to buy new ones....................Wink
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/23/2009 at 10:04
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....if you can find 'em!
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/23/2009 at 19:38
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Most dies are ok.  Most chambers are ok. 
 
Most cases aren't ok, at least not at first nor do many loaders do the things needed to reduce runout.  
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/26/2009 at 05:51
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Thanks for all your input. Some food for thought which I will digest and take a new look at  "bullet run-out" .
Thanks Texas, some good info you have posted.
 
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/27/2009 at 07:50
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Consider this;
We load the perfect round with zero run out.
Then we put it in the rifles magazine, cycle the bolt rearward, and with some degree of force we run the bolt forward.
The bolt face strikes the cartridge rim pushing it at some velocity forward into the feed ramp and bending the bullet, and we hope, the case, upward.  Next the bullet strikes the top of the chamber just before the cartridge rim frees itself from the magazine to allow final alignment with the chamber.  The bolt at this time is still applying forward pressure onto the cartridge.  Finally the cartridge chambers and the bolt closes.
 
What is now the run out on our deformed cartridge?
 
It's a big box.  You don't have to think outside the box, just be sure to look in all 4 corners.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/27/2009 at 09:35
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Mike, I see your point I guess, but I think of improper feeding from the magazine as a separate issue from handloading concentric ammunition. To me a rifle that deforms ammunition when feeding needs to be improved or repaired. One could say that there is no point in correctly calibrating the oven control because the chef might set the temperature wrong or put the cake pan on the wrong shelf... but I would disagree.
 
I prefer to achieve the best handloaded ammunition I can reasonably assemble, and then use that ammunition in the most accurate and properly functioning rifle I can reasonably obtain for my purpose. Sometimes that purpose is competitive shooting and sometimes it is hunting and so the definition of properly functioning rifle or handloaded to the proper level of precision may vary; however, none of my hunting rifles appreciably deform my handloads when feeding from the magazine. I know this because I have measured the ammunition before and after, and I have slicked up feed rails, etc. when required to achieve proper feeding.
 
So, you are correct that a malfunctioning magazine rifle can negate all the virtues of "the perfect round with zero run out." My view is the proper reaction to that condition is to make the rifle feed better, rather than to abandon the objectives of precision handloading. That is just me though, everyone's definition of good enough is their own opinion in the end.
 
Good shooting,
 
Texas
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/27/2009 at 18:56
Mike McDonald View Drop Down
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I was speaking of the events that occur when a cartridge is chambered in a properly functioning rifle  Emoticons
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/27/2009 at 20:42
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Mike, there is a possibility that chambering or ejection of a loaded round could push a bullet out of concentricity.  In my tests in my rifles it hasn't happened yet.  The reason I say this is that a case goes through phases from new to work hardened that all effect the ability to move the loaded bullet.  I use a Bersin Tool to not only measure runout to a finer degree than most concentricity gauges (each graduation 4/10,000th of an inch) but also allows me to push on the bullet and reduce runout
 
IME the force necessary to move the bullet is progressive in that new case = less force, work hardened case = more force.  So it is extremely easy to push the bullet seated in new cases (you can create runout by hand if you're not careful) and the work hardened necks are harder to push but easier to make stay there once you get them in line.  With new cases it takes such little effort to push the bullet that you wind up pushing the runout from one side of the case neck to the other.  Now on all of these to date I have been sizing with the Lee Collet which does not give very much bullet grip and now I am starting to experiment with more grip from bushing dies and smaller Lee Collet mandrels.  Perhaps they will be easier to reduce runout on and have it stay there with greater bullet grip.  Will advise.
 
Where 8shots is going wrong in his original thesis is that if you are sizing and reloading cases and you measure a few that have very little to no runout, then all of them will be that way.  Not so.  In a batch of 50 or so loads I will be trucking along with the dial only moving 2 or 3 graduations (which I will not try to fix as it will just go from one side of the case to the other and bullets are not perfectly round) when all of a sudden one will have significantly more.  That is the one I reduce to be in line with the others.
 
So even with good loading practices and dies it is possible to get the occasional loaded round that has more runout than the others.  Look for that one and either sort it for a sighter or straighten it.  There are several ways to straighten the case and reduce the runout;  ie block of wood with appropriate sized holes or holding the necks in a collet bullet puller, probably some others that loaders have discovered.
 
In retrospect, I would have to say that discovering better loading practices to reduce runout has been at least as important as the actual runout reduction itself.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/27/2009 at 20:57
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Excellent post!

I'll just add that I've drilled a series of holes in the 2x6 that's the front of my loading bench that run from .2  on up. They're there to "tweak" the bullet run-out in those odd rounds that don't conform to whatever standard. Just insert the bullet and lean on the case a little...

This doesn't help if the bullet is really out of line. But most rounds can be tweaked--and it does help.

Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/27/2009 at 21:10
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 I think we could look at it from the standpoint that if runout is that easy to aquire accidently, than it stands to reason that it is probably just as easy to 'accidently' remove most of it by chambering that crooked round in a good barrel that has been chambered straight to begin with.

 I suspect this may also be the real underlying reason so many handloaders get the best results with bullets seated very close to or just touching the lands. The leade is then applying a little pressure to the bullet and thus helping align everything concentrically before takeoff.
 What do you guys think?
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/27/2009 at 22:24
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I do think that seating into the lands does remove the runout problems.  Benchresters do it all the time from what I hear but they are shooting loads that are not maxed out.  I have loaded into the lands and had good results with only a small increase in velocity.  Mostly that was to trying to reduce case stretch in new brass.
 
But, I have had very poor results trying to seat close to but not into the lands.  IMO it is best to seat into the lands or at least >.020" off.  Anyway seating close to the lands would not alleviate the runout concerns like seating into the lands.
 
I have measured runout before chambering and after chambering rounds and can find no change, even with new cases.
 
Another thing that will add to runout is a batch of cases that have a lot of neck thickness variation.  Sorting cases according to neck thickness can weed out the bad ones.  The thickness is not as important as the amount of variation from one side to the other.  Reference this diagram that shows how a case with a thick side and a thin side has been produced off center to begin with
 
even outside neck turning can not correct these kind of cases.
 
Runout can be reduced by outside neck turning on good cases.  It will depend upon what kind of die you are using.  If you are using a bushing die without the expander then neck turning is very helpful because the bushing die will push all the variances to the inside of the neck where the bullet will get pushed to one side during the seating process by the thicker neck brass.  If you are using a Lee Collet then the variances will be on the outside and your neck runout may not be perfect but the bullet runout will be OK.  With a FL or neck sizing die and an expander ball the variances will again be on the outside but it won't matter because that stupid expander ball will play hell with your runout anyway (unless you have tuned it)!
 
Seating can cause runout if your bullet grip is too heavy.  A good competition type seater which supports the case body and holds it in line with the bullet seating stem at least will not create problems although IMO it will not straighten a crooked case.
 
I have pretty much stopped chasing concentricity and I sleep better at night.  But before I stopped I had pretty much chased it back into it's den and keep it there with the loading techniques I learned while going crazy chasing it.
 
I know, too much information.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/27/2009 at 23:45
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Ok guys, great posts and a confession from me.
Please read the post.carefully.  Last part was a question, not a statement.
 
Now read the part concerning the box.
 
Ya'll did a fine job of looking in all the corners.  Great posts!
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/28/2009 at 02:54
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Thanks for all the feedback. Some very interesting points have been raised.
 
I will take another look at my entire reloading procedure. I will also put my runout gauge back on the reloading bench.
 
 
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/28/2009 at 08:19
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Good morning all,
 
This is or has been a very interesting discussion to me, and I am enjoying the various bits of information! I thank you all for your excellent posts! Thank you for starting it 8shots!
 
Sakomato, from where did you obtain those Bersin runout straightening/measuring tools? They look like something worth having to me. Have you read Creighton Audette (I think - been a while) in Precision Shooting on this subject? By the way, I have an SG&Y Rifles (Speedy Gonzales) custom 280AI that shoots lights out. How do you find yours?
 
Mike, your question at the end of your original post is certainly well taken, and I appreciate your contribution to this discussion. Certainly you provoked a bit of critical thinking on my part.
 
John B, I think I must have had some of those dies you mentioned. They are now used for fishing sinkers... Ha!
 
Good shooting all!
 
Texas
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: May/28/2009 at 18:59
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Hey Texas
 
I got the Bersin from Kinneman's but that website is no longer available.  Perhaps if you did a search for the Bersin you can find one.  It was not cheap, about $300.00 if I remember.
 
Hornady is coming out with a new concentricity gauge where you can push on the bullet soon
 
actually it looks like the tip of the bullet and the case head are held in place and you push on the neck.  Either with the Bersin pushing on the bullet or the Hornady pushing on the neck is going to have the possibility of canting the bullet in the neck.  The Hornady may be better in that when you push on the neck you are actually aligning the tip of the bullet in line with the case body rather than aligning a point on the ogive in line with the case body.
 
It is far better to purchase good cases, not create runout when resizing the neck (by whatever method you choose) and seat the bullet straight with minimal force.
 
Originally posted by Texas Texas wrote:

By the way, I have an SG&Y Rifles (Speedy Gonzales) custom 280AI that shoots lights out. How do you find yours?
 
Mine is a rebarrel of a Sako 75 action, from 270 to 280AI, done by Hart 1 in 8.5 twist and it is a good shooter but develops do-nuts big time with Nosler 280AI brass.  It is my "pivot" rifle in that if I am going Whitetail I'll carry the 280AI and my 6.5 rem mag or if I'm going Elk hunting it is the 280AI and the 338RUM.  It is stainless so I always have an option for a rainy day.
 
Hey JB, did you drill your holes in your wood on your bench to go over only the bullet or go over the case neck?
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: June/01/2009 at 14:30
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Sakomato, you are the second to tell me about that new Hornady rig. I think I will get one when they are available, the Bersin set up doesn't seem to be around.
 
My 280AI is built on a Rem 700 action blueprinted and trued with a Shilen Select Match SS #5 taper barrel pillar bedded in a black Mickey Rem Classic stock. My all-time favorite whitetail rig - although I'm flirting with 338 WinMags these days of hunting horns and any shot I get thang...
 
Texas
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: June/01/2009 at 19:34
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One thing I am personaly convinced of, after fooling with this for a while, is that heavier bullets tend to straighten out in the rifling ahead of the throat after being fired, evfen if they're seated slightly crooked (emphasis on "slightly"). This is particularly true if the bearing surface of the bullet is fairly long.

Bullet "hardness" might also have something to do with it. A monometal hunting bullet certainly would have a tendency to follow the bore, partly because it doesn't have a thin jacket and soft lead core, and partly because it would be longer for it's weight. This would help explain why the Barnes TSX and other monometals shoot so well in many rifles. 
 
Of course, heavier bullets that aren't too long to be fully stabilized in the barrel's twist also might shoot better because they match the twist closely. But I am pretty certain that both factors are at work.
Post Options Post Options   Thanks (0) Thanks(0)     Back to Top Direct Link To This Post Posted: June/01/2009 at 20:32
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Hmmmmm, heavier bullets....Ditto
 
I have seen what you are talking about with accuracy happening with the heaviest possible bullet before the twist looses it's grip.  I had a Sauer lighweight 30-06 that I absolutely loved but I tried every bullet and powder combination
 
165 gr - Partitions, TBBC, TSX, Ballistic Tips, NorthForks
168 gr - TSX
175 gr - Sierra MK
180 gr - Partitions, TSX, Failsafes, Ballistic Tips, Sierra Game Kings
 
all with every powder from IMR4350 to RL22 and was not satisfied until I tried the 200 gr Accubond and RL22.  Now it would not shoot the 200 gr TSX and would keyhole with that bullet which was too long but it was 100% consistant with MOA with the 200 gr Accubond and 60 gr RL22 and Fed215's.  So the 200 gr AB was right on the verge of being too long for the 1 in 10 twist but gives excellent accuracy.  Matter of fact I have yet to see any of the 30-06's I reload for (8) fail to shoot that load.
 
Perhaps the slower powders used for the heavier bullets contribute by slowing down the force behind the bullet rather than slapping it out of the barrel.
 
Who knows but I am definitely a member of the Heavy Bullet Mafia!
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