Straighten or index

A

Andy Cross

New member
I have had a discussion with some BR shooters and there is some disagreement on whether bullets should be straightened after measuring the run out with a concentricity gauge or just indexed. By indexed the person meant putting a felt tip pen dot on the round so it could be placed in the chamber the same way each time. Having the bullet seated into the lands would straighten it anyway. Or straighten the bullet even though it will probably be chambered on to or into the lands anyway.

My thoughts are if jamming the bullet into the lands does in fact straighten the bullets why measure the run out in the first place.

Your thoughts would be of interest.

Andy.
 
I'd be interested in hearing the general consensus on this topic.
 
GaCop said:
I'd be interested in hearing the general consensus on this topic.
Click to expand...

Or at least some opinions. I know making the cartridge straight to begin with is best, but sometimes that doesn't happen. So I straighten the cartridges - stick them in what looks like aluminum angle with holes in it and bend them straight - sort of brute force but it works and takes remarkably little force.

It makes no sense to me to work so hard to get a chamber/throat/bore aligned to tenths of thousandts and then put in a cartridge with it's nose off in some direction two or three mils.

I like my RCBS measuring tool because it also allows me to measure case wall thickness and look for stretching, but it was frustrating because I could see the needle move and not fix it. The simple solution for straightening seems to work.

Fitch
 
Andy, you are making a false assumption.

Chambering a crooked round will not starighten it. I have checked this, and it simply does not happen.

I have also fired rounds that were as much as .003 crooked, and they went into the same hole as ones that were less than .001.

We do a lot of straightenning in our shop, you learn a lot about how materials act when subjected to a particular force. I have often wondered about how various round straighterners. I have always thought that there is the possibility of actually bending the bullet than moving it in the neck. ........jackie
 
jackie schmidt said:
Andy, you are making a false assumption.

Chambering a crooked round will not straighten it. I have checked this, and it simply does not happen.

I have also fired rounds that were as much as .003 crooked, and they went into the same hole as ones that were less than .001.

We do a lot of straightening in our shop, you learn a lot about how materials act when subjected to a particular force. I have often wondered about how various round straighteners. I have always thought that there is the possibility of actually bending the bullet than moving it in the neck. ........jackie
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OK, let me say right up front, I have no indispensable ego attached to anything in this reply, so have at it. I'm in learning mode.

I wondered that too. So after I straightened them, I did some checking to see how they tested. I didn't see any evidence of the bullet being bent.

I use this tool http://trutool-equipment.com/ to straighten the rounds. My biggest problems have been with 7mmMAG though I seem to have solved part of the problem anyway. Some of them were as much as +/- 0.006" (0.012" total indicator movement). Lately they have been better, about half that, but I have no clue why.

I have some heavy aluminum angle in the shop and have thought of running a chamber reamer into it up to the base of the neck to get a better fit on the neck of the cartridge but I haven't done it yet. I also thought of trying to ream a hole that was groove diameter + 0.001" or so to bear only on the bearing surface of the bullet but discarded that idea as impractical since it would require a custom set of reamers.

I have a cut off chunk of .308 barrel blank that I could push my .30-06 reamer into with the idea of making a tool that fits the neck but I haven't done that yet either.

I was surprised at how little force to get the bullets to run within 0.002" total indicator movement. I think the Hornady tool may be a better combination if eccentricity is the only concern, but I didn't get it because it does bear on the tip of the bullet which is probably more vulnerable to distortion than the neck and the bullet body before the ogive which is where the current tool exerts force. OK, a few thousand words worth of pictures ...

This shows a dummy round in the tool from the case side. I normally pull up but the effect is the same either way. The edge of the tool bears on the neck of the cartridge close to the base of the neck.

TruTool7MAG-2-C.jpg


This shows the other side of the tool. The aluminum tool bears on the bearing surface (full diameter) of the bullet just beyond the neck.

TruTool7MAG-1-C-RS.jpg


Those look to me like they might be the best places to put pressure if one is going to try to straighten the cartridge.

The case at the base of the neck is still supported by the bullet so it takes a lot of force to dent it. The body of the bullet at full diameter is pretty solid and given the low forces being used doesn't seem likely to be deformed. I don't see any deformation on straightened cartridges anyway.

Anyway, the process is dirt simple and results in what measure as much straighter cartridges than I started with. The only ammo I seem to have to use it on is .30-06 and 7mm Rem MAG. .22 Hornet, .223 and .17 Rem seem to come out straighter. .243 I sometimes use it but not often.

Fitch
 
Fitch, most straightenning tools support the bullet up close to the tip, and the case up toward the rim. Force is exerted on tyhe high side at arount the shoulder. This does put stress on the bullet for it's length.

Your method does seem to eliviate much of this problem........jackie
 
I've never concerned myself with the straightness of whatever I cooked up in the reloading cycle. Merril Martin wrote a rather convincing article as to the effects of such and evidence that indexing improved accuracy. That article bothered me a bit in terms of how much "agg" I was leaving on the reloading table but, again, I never pursued the issue. I rationalized that if I won a match and lost the next without changing reloading technique then there was something else afoot that caused me to win or lose.

The competition benchrest shooter doesn't have time to index nor can he live with the distraction. Certainly he has plenty of time to index and fire the required number of shots but in reality he has 7 minutes to choose the right 30 seconds in which he will shoot his bullets. Sooooo....if you're gonna fool around with runout, make 'em straight right out of the loading process.
 
If I was worried about .0000 of runout and couldnt get it out neck turning Id do some cullin. I know at Lake City when the wall thickness was bad on the case cup on first draw by the time it got to us on taper we couldnt straighten it out. I know were talking benchrest now but its same principal. Crap in crap out. Doug
 
Conclusions

Just bear with me for a moment.This is an excerpt from Tony Boyers book Rifle Accuracy.

"When shooting with a bullet into the lands, the lands themselves straighten the bullet without forcing over-travel. To straighten the loaded round the bullet is pushed significantly past the point of zero concentricity bending the case neck. I cannot believe that this does not infulence neck tension on the bullet. Something we strive so hard to be the same from round to round. I let the dies and the lands take of concentricity."

So what I am getting so far from this thread is that the information above is actually wrong. If you want them straight you have to straighten them. Unless the run out is quite bad it probably won't make any difference and that most shooters wouldn't have time to do any measuring or straightening at the loading bench at a match anyway. I think I am a tad more confused than before I posted the thread.
Andy.
 
Another thing, Wilbur, was that Merrill Martin was always using factory chambers. IIRC he got a "benchrest" chamber once & had oh-my-god moment.

To the posed question, I say "neither." This after an awful lot of rounds down the range at 1,000 yards, where it should show up. -- Except, except, I took some pains to get 'em straight to start with. For about 5 years, I sorted what I just loaded, & the "match" rounds had .0015 or less. They shot just as good as the ones that didn't. The worst, which would be "foulers" might reach .003. Life's too short, & there are so many other ways to contemplate sorting your rounds.
 
Andy the following will accurately describe how you feel now.

I fully realize that I have not
succeeded in answering all of your
questions.

Indeed, I feel I have not answered
any of them completely. The
answers I have found only serve to
raise a whole new set of questions,
which only lead to more problems,
some of which we weren't even
aware were problems.

To sum it all up...In some ways I
feel we are confused as ever, but I
believe we are confused on a
higher level, and about more
important things.
 
I'll agree with Charles, the only answer is "neither."

If your rifle makes crooked cases it's buggered up.

If your reloading system makes crooked rounds, IT'S buggered up.

Fix the buggerups, fix the problem.

al
 
for those that cannot read english
fix the PROBLEM, not the symptoms


mike in co

alinwa said:
I'll agree with Charles, the only answer is "neither."

If your rifle makes crooked cases it's buggered up.

If your reloading system makes crooked rounds, IT'S buggered up.

Fix the buggerups, fix the problem.

al
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I will have to disagree with Jackie on this one. I have an H&H concentricity gauge, that can be used to measure loaded rounds and straighten them. Once, with brass turned to produce neck clearance of slightly over a thousandth, I used the straightening feature to bend a loaded round to the point that it had a TIR of about .0035. The bullet was loaded to a length that was a few thousandths off jam, with a neck tension of .003. After chambering the round, I remeasured it and the TIR was about .0015.

It would seem to me that a good question to ask is how crooked ammo can be before it shows up on the target. Of course the question is specific to tight necked short range benchrest rifles of the highest quality, well driven in ideal conditions. I have been told, by one of a long list of my benchrest betters, that anything that is under .002 on the bullet, is good to go. My stuff has recently gotten straighter with the addition of a carbide bushing, and the discovery that I have a steel bushing that is much straighter than the rest of my small collection. I think that the best uses for concentricity gauges are to diagnose reloading equipment, and more importantly, screw with people's self confidence.;)
 
Is it a problem

alinwa said:
I'll agree with Charles, the only answer is "neither."

If your rifle makes crooked cases it's buggered up.

If your reloading system makes crooked rounds, IT'S buggered up.

Fix the buggerups, fix the problem.

al
Click to expand...

My rounds when checked with a sinclair concentricity gauge (not mine I don't own one) read a maximum of .001 runout with the majority around .0003 From what I am hearing I don't have an issue with concentricity. But if this amount was an issue straightening them is not advisable because it might bend the necks. Leaving them the way they are might also be unadvisable even if there was time to measure and correct. So is my system buggered up or not. Everything is as clear as mud now.
Andy.
 
Is it a problem

Andy Cross said:
My rounds when checked with a sinclair concentricity gauge (not mine I don't own one) read a maximum of .001 runout with the majority around .0003 From what I am hearing I don't have an issue with concentricity. But if this amount was an issue straightening them is not advisable because it might bend the necks. Leaving them the way they are might also be unadvisable even if there was time to measure and correct. So is my system buggered up or not. Everything is as clear as mud now.
Andy.
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no

IMO your inbore yaw will be exactly 1/2 your total neck clearance. It HAS to be. "Concentricity of your loaded round" simply shows the play or clearances and misalignments in your system. Straightening does nothing to help

In My Opinion

al
 
I have never owned a concentricity gauge or a ball micrometer.

Everyone talks about turning necks to this or that thickness........ means nothing to me as I rely solely on my outide micrometer for loaded neck dimensions.

Concentricity I really do not want to know.

If I were to buy a concentricity checker which is the NO brainer to get. I tried the RCBS and honestly felt it was a piece of junk....

Thoughts on this????????

I rely solely on the guy cutting my chambers that he is doing his best and Harrell's that they are making a STRAIGHT die. My Partner press............ Well who knows? I just feel the looser the press the better......

Calvin
 
I will make a bet with anybody who wishes to take me up on it.

Take a case, and full length size it the way 90 percent of Benchrest Shooters do. That means the case will slip in and out of the chamber with no resistance. Seat a bullet, making sure that the bullet is at least .010 into the lands. Before you chamber it, check the runnout. For this test, I would like for it to be at least .0015.

Chamber the round and then take it out. You should be able to see distinct bullet marks on the bullet. Check the runnout again using the same method as before. I will bet good money that it will not be any truer than when you checked it the first time.

The reason I know this is the same reason I know a lot of things. I don't depend on someone else's word, I actually do it for myself.

Saying that a crooked round will straighten out when chambered tells me that who ever makes the statement has never actually done what I said to do..........jackie
 
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