Straighten or index

Throat

macaver1 said:
Greg Tannel has done my smithing (at least 2 barrels a year for several years) so I'm not worried about the quality of the chamber.
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I'm familiar with Greg and his work so I believe you. I've shot some of his rifles. I would think after fire-forming your brass in one of his chambers run out wouldn't be an issue. - nhk
 
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nhkuehl said:
I would think after fire-forming your brass in one of his chambers run out wouldn't be an issue. - nhk
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That would only be true if cases with thickness variance(they all have some degree of it), had been neck turned.
And then it would only hold -until you FL sized.
You let the jeanie out full length of the body at that point, and as mentioned, it can never be straightened from there. It only gets worse with each cycle.

To keep ammo below 1thou TIR -off free bullet noses:
Cull by thickness variance (<1/2thou)
Turn necks
Use tight chamber clearances
Minimally size(NEVER FL size)

I realize none of this will happen here, but it should be said, and recognized.
 
An overlooked factor in reducing r/o is that the case necks be perfectly round and not tapered. Normally this isn't a problem when the case hasn't been necked up/down, as in a 6BR. When you start expanding necks up or down, things can get herky. Inside case neck can be easily checked any number of ways. -Al
 
This isn't my thread and I'm not a group shooter, but I use (unprepped) Lapua brass in no turn necked chambers and neck size with bushing dies and run out is 0.003" or less and I leave it at that. I'm shooting long match bullets with a long free bore and the free bore probably does more alignment than the neck. I've also removed the ejectors from my free floating bolt heads and the firing pins print on center. The rim diameter of the Lapua .308 brass was 0.010" greater than Federal brass I started with and that improved accuracy. In the whole picture bullet runout may be a minor(?) factor. - nhk
 
I have spent a fair amount of time working on concentricity of PPC brass. If you fire form with pistol powder or by firing a .22 bullet down a 6mm barrel (I turn to just over finished thickness at .22 cal. first (.262 neck).) the result will be quite a bit straighter than if you expand up with a mandrel. Whether the difference will show up on paper, I leave to others.
 
Andy regarding your post #10 and Tony's quote, IF you read Mike Ratigan's book he states (the same as Jackie) that putting a crooked round into the chamber will not straighten it.
Tony also stated somewhere in his book that he was not worried about runout as he has not found it to be a problem.

As far as runout goes it might be best to try the runout test first on a fired case that has not been resized then one that has been resized and then fineally a loaded round checking the neck and the bullet.
Could be the chamber is out to start with. If not then either the sizing or seating die would be bad or so it would seem.

Mine are concentric when they come out of the chamber. BUT....last year I tried annealing some brass and it made it crooked, about 7 thou out. Running it through my die didnt change a thing. However after firing it once it was again .001 or less out.
So my chamber is good but my die wont fix a crooked case.
 
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Boyd Allen said:
I have spent a fair amount of time working on concentricity of PPC brass. If you fire form with pistol powder or by firing a .22 bullet down a 6mm barrel (I turn to just over finished thickness at .22 cal. first (.262 neck).) the result will be quite a bit straighter than if you expand up with a mandrel. Whether the difference will show up on paper, I leave to others.
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Forgive my newbieness here, but do you mean size down to .22, fireform in 6ppc barrel, then return to regular 6ppc scheduled programming?
I'm doing a lot of decision making on which way to go bringing .308 down to .243 without inducing a mess of error into the cases before it even gets to loading.
 
Read both books

One of the reason I posted this thread is because I have read both books which seem to contradict one another. Nothing new in this game I know. My rounds only exhibit a maximumRO of 1 thou most of them about half that. So it probably isn't an issue. But as I have also read in the book rifle accuracy facts. In it the author states that a bullet that has a tapered after body can - cant - in the barrel which means even if things are concentric to begin with the bullet may still leave the muzzle crooked. This would negate most of the work done to gain good concentricity in the first place.

Any thoughts forum members have on this would also be appreciated.

Andy.
 
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I don't advocate straightening rounds, though I have straightened lots of them. Necks seem to bend easily and this loosens
the grip the neck holds on the bullet. Some powders are more affected than others and when you introduce another variable
its not known what the affect is.
Lumping all this together as good or bad just won't do it for me. Flat base bullets with a very prominent expansion ring
and seated a very short distance in the neck are straightened with little force. On the other hand, boatails seated quite
deeply can require a serious amount of force, given that situation, some necks get bent when in fact it was just the bullet
that is out.
Once you have a die that produces straight cases, it is the seater that needs tested. Anything that allows that bullet and
case to misalign causes runout. All seaters will allow it to some degree. They must , because enough clearance is needed
to remove the round from the die. We can however minimize it.
 
LorenC,
Starting with an new .220 Russian case, expand and turn at .22 cal to .010 neck thickness. Then either use the pistol powder NO BULLET method to fire form, or load with a powder of suitable speed for a 6PPC and an inexpensive .22 cal. 55 gr. bullet, and fire in a 6ppc fire forming barrel, then expand to 6mm and turn to final neck thickness. If the latter method is used, move close to your back stop if it is of minimal height (as many are). The reason for turning at .22 caliber is that with a .262 neck there is still enough expanding to do at 6mm of an unturned neck, that some case distortion results. Another point needs to be made. On the bullet concentricity numbers vary with the kind of gauge as well as where the reading is taken on the bullet. Because this is the case, it is really difficult to know that you are talking apples for apples unless you use the same gauge and setup to measure the ammunition that you are comparing.
Boyd
 
That question on cant

I have also read in the book rifle accuracy facts. In it the author states that a bullet that has a tapered after body can - cant - in the barrel which means even if things are concentric to begin with the bullet may still leave the muzzle crooked. This would negate most of the work done to gain good concentricity in the first place.

I would still like members thoughts on the subject I posted above in a previous responce. It is something I have never thought about until I read this book.
Andy
 
So, we have competing Icons, one says one thing in his Book, another says just the opposite in his Book.

All of this is really a moot point as to who is "right', because any one can simply check these sort of things for themselves.

Check a round for straightness. Then chamber it, and remove it. Check it again.

As I said before, I would bet good money that if it was crooked going in, it will still be crooked coming out.
 
Jackie I think you are right.
Thats why I listed the process earlier.
HOWEVER since you are only willing to bet GOOD money, that might indicate you have some old dirty bad money laying around. Send me your address and Ill send you a prepaid box you can put it in, and Ill get rid of it for you......:rolleyes:
 
One thing I'll bet on, if you chamber a loaded benchrest cartridge in a benchrest chamber with the tolerances we normally use, if that bullet/case neck is running out say 0.005", it will chamber and shoot very well. If you just chamber it and remove it the runout will probably still be there because you would have to go past straight to remove the free-cartridge runout and just chambering it will not take it past center. In a factory chamber, this is not the same since a factory SAAMI can be as much as 0.010" clearance whereas a benchrest loading will be not over 0.004" total clearance, most benchrest clearances will be closer to 0.002", sometimes less.
 
With neck clearance of between .001 and .0015 a round that was bent to a total indicated runout of about .0034 was chambered in a .262 neck 6mmPPC chamber and then removed. The seating depth was a few thousandths off jam. When the TID of the round was measured, after being chambered, it was .0015. I did it. Perhaps some of the probably, should be, and maybe guys should simply step away form the keyboard and actually do the experiment.
 
Boyd, for something to have an affect on something else, such as a bullet being straightenned by the lands as it is chambered, wouldn't the bullet have to make contact. "Seatin depth a few thousanths off jam". What caused the bullet to straighten.

I have one of the Bruno Round checker-straightenners, and it takes a pretty good pop to make things change.

The only reason I as is I have done this quite a few times, with everything to just touching to hard jam, and the things simply do not straighten when chambered.
 
Jackie, I am not contesting what you have done. We are working with different tools, and they may yield different results. If you know someone near me that you would believe, I will be glad to demonstrate. Over the years I have seen several tools that can be used to straighten and measure how straight ammo is. As it happens, one quite a while before Lester came out with his. Having used both types, I prefer one that allows me to push on rather than "pop" rounds to modify their straightness. Once, I took an H& H to a match and straightened all my rounds as I loaded them to about half the runout that my seater produced, that and measured several other shooters ammo. I am of the opinion that these tools are best used to check reloading equipment, and have not found any advantage by reducing runout from around .0015 to half that, but I have found that by using one, I have been able to significantly improve average runout by comparing the results of various reloading tools and accessories. Given the trouble that you have gone to to custom fit a one piece sizing die, I would be surprised if you have any concentricity issues. Have you seen any on target result from straightening your ammo? Added later: by a few thousandths off jam, I meant something like .003, and with a little over .003 of neck tension, and an ogive shape that produces long rifling marks at that depth. The longs were quite a bit beyond square. The bullets Tucker #3s with a .060 freebore, and about .135 in the case, in a fresh chamber. The Tuckers have a larger pressure ring than most, and a slightly larger than shank diameter section just in front of that. These factors may have contributed to the difference in our results, since I believe that your throats are shorter and your bullets may not be shaped to pivot so easily in case necks.
 
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In an attempt to find resolution, with absolutely no data, the difference I notice between Jackie and Boyd's test is, I think, Jackie started with rounds "naturally" off-center, whereas Boyd started with rounds pushed off center. My first thought was that Boyd's rounds were simply returning to the state they were at when loaded. Absolutely no data to support that, but perhaps worth a test? -- If Boyd can actually load a round where the bullet runs out...:)
 
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