Concentric bullet seating - tolerances?

H

HopeToBe

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After spending time with my seater I am starting to get slightly uncomfortable with it in the sense that I expect it not to be concentric enough. It is kind of not "tight enough". So what tolerances should I demand when measuring the bullet concentric. Should it be absolutely 0 or is 1-2/1000'' OK?
 
If you are loading for a benchrest tolerance chamber and seating the bullet to any amount of touching the rifleing in the leade the bullet will straighten itself when chambered. This is not to say that a lot of runout of the seated bullet is acceptable.

Much bullet runout in normal reloading dies is caused by the expander as it comes back through the neck. Benchrest sizing dies do not use an expander.
 
However if you jump your bullets then the chamber isnt going to help much is it?
 
I'm w/Jerry

...............or, you can purchace a concentricity tool and bend your case necks while getting the bullet into "just perfect alignment!
 
Jerry
I didnt find your statement to be true. Ill explain. After reading your response i took a 30BR case i had loaded a couple nights ago that has about .003 runout. I stuck it to the side as i was going to use it as a fowler, but i thought i would see what happens after reading your response. The bullet is set .022 past jam in my chamber with about .004 neck tension. I chambered the live round out side and closed the bolt. I could feel the resistance from the bullet being set so long, and it actually pushed the bullet back into the case about .010. anyway I re-measured the case in my sinclair tool and it had the exact same run out as before. I wonder why?? Now maybe the brass wasnt turned properly or maybe there's something else going on with this particular piece of brass were it will never be straight, Im not sure. However it didnt straighten itself even with the bullet well into the lands.. Maybe .004 neck tension is to much? There again, i dont know. Any thoughts?? I dont have any issues with any of the other 20 pieces of brass i have been working with.
Also sir please dont think im calling you out here because that isn't what im trying to accomplish with my response. Im just always eager to learn a thing or to here, thats all. thanks lee
 
Playing around with an H&H concentricity gauge, I "straightened" a .262 neck 6PPC round to about .004 runout, chambered and unchambered the round, and rececked the runout. It was about .0015", this with a seating depth that produced marks on the bullet, and about .003 neck tension.
 
skeetlee said:
Jerry
I didnt find your statement to be true. Ill explain. After reading your response i took a 30BR case i had loaded a couple nights ago that has about .003 runout. I stuck it to the side as i was going to use it as a fowler, but i thought i would see what happens after reading your response. The bullet is set .022 past jam in my chamber with about .004 neck tension. I chambered the live round out side and closed the bolt. I could feel the resistance from the bullet being set so long, and it actually pushed the bullet back into the case about .010. anyway I re-measured the case in my sinclair tool and it had the exact same run out as before. I wonder why?? Now maybe the brass wasnt turned properly or maybe there's something else going on with this particular piece of brass were it will never be straight, Im not sure. However it didnt straighten itself even with the bullet well into the lands.. Maybe .004 neck tension is to much? There again, i dont know. Any thoughts?? I dont have any issues with any of the other 20 pieces of brass i have been working with.
Also sir please dont think im calling you out here because that isn't what im trying to accomplish with my response. Im just always eager to learn a thing or to here, thats all. thanks lee
Click to expand...

Skeet, if you want the bullet straight in a relaxed condition out of the chamber then you have to bend it PAST to tweak the neck. Then what? The neck tension for that cartridge is screwed up that compared to the rest of that batch. Now then, how much do you want to bet me that the bullet was not forced into alignment WHILE IT WAS SEATED IN THE CHAMBER? That is where the rubber meets the road.

Comprande'??
 
Some Issues:

One, Carbon build up will make good seating extremely difficult in terms of corect OAL's and perhaps straightness. I have never checked for straightness believeing the barrel will take care of all that.

In my opinion, it is far more important to make certain the OAL of loaded rounds is kept within .0005 ( YES, that close) measured where the bullet will touch the lands. From 10 or more years of tuning, I have learned that this measurement is what makes the single small hole, providing all else is proper.
 
Fair Enough!! I wasnt doubting you though, just stating my findings. I guess i wonder why straight ammo is even an issue if it straightens itself if seated into the lands? I still like my ammo to be as straight as possable. Thanks lee
 
I think when you put 50,000 PSI behind that bullet it will staighten it more than any gauge. This is also the thoughts of the most Honored shooter among us. It is in the book. But if you think it works better for you to straighten your ammo go ahead. Its time & money for another gadget we probably don't need. Tony
 
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Well, I would rather not straighten rounds, I would rather work with the sizing and seating operations untill the rounds consistantly run .001 or better. Both my 6PPC and 30BR do just that.

That is what I do not understand. If your rounds are not straight, do something about it, rather than just fall into that herd mentality of "it doesn't matter". ..........jackie
 
No, David it is not. It is about the gadgets and spent money that actually do some good.

Regardless of what Tony writes in his book, I would bet a paycheck that he DOES NOT settle for rounds that run out .005+.........jackie
 
jackie schmidt said:
Well, I would rather not straighten rounds, I would rather work with the sizing and seating operations untill the rounds consistantly run .001 or better.
Click to expand...

This was sort of my intention as well with the question, controlling my setup to be "straight enough" and not to test every single round out on the range.
 
Hopetobe Jackie is right.
Your primary goal should be to find out WHY your rounds are not conentric in the first place.

On another note. I have Tony's book but have not read it yet HOWEVER if you want to quote from books from guys with big names... read Ratigan's book he addresses the fact that bullets wont self center and have to be concentric BEFORE they go into the chamber.
That is if you have to have some one with a book to their name, otherwise Jackie has or will have a world record agg under his belt and I have been listening to him for years and must say he has helped me a lot.
Thanks Jackie.
 
Vern, I am in NO WHERE NEAR the league of a Shooter as Tont Boyer. Heck, he is Don Drysdale, and I am just a guy with a decent slider trying to make a living in AAA. But then, Tony does seem to be in a league of his own.

But, I am not stupid. I have been around Tony, and other top Shooters enough to know that they leave very few stones unturned. The meticulous preparation that they put forth in every avenue of accuracy leaves me to believe that they would show the same consideration to the loaded round as well.

To the novice Shooter, a confusing situation could present its self when two top Shooters write, in their own publications, things that seem to be an opposite train of thought. It doesn't help when posters come on this site and say "none of that matters", when the reality of Benchrest has taught us that, in the end, everything matters.

I go back to my originol statement. If your rounds are running out, find out what is causing this. That would seem a better solution than simply saying "it doesn't matter'.........jackie
 
Jackie I do have a question and story about concentricity I need to figure out.

I annealed some brass and the cases came out up to .005 or more out some way out.
Lets leave that part alone, does not matter.

The problem is I thought I could straighten them in my sizing die.
Ran them up and bottomed them out.
Nothing same in same out.
I fire formed one of them with bullseye and bingo back to less than .001 whats up with that?
When I put it in the die it stayed less than .001.
My situation is that my die does not change a thing but the chamber in my gun is really really close.

Do I need another die or am better off this way? That is the question.
 
With the right brass, dies, setup and procedures 0.0015 on the bullet, just north of the case mouth can be obtained even with standard length cartridges.........................

With BR cases 0.001 or less should be normal with the right brass, dies, setup and procedures.

If not check your brass, dies, setup and procedures.
 
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