Hornady Concentricity Comparator/Corrector.

[camac]

Thought I would take Toodogs lead and post a pic or two to discuss.

NOTE: smaller runout measured by hornady and bruno......

 

[toodogs]

Excellent illustration camac! well done!

 

[camac]

No worries Toodogs - as mike said - sometimes it is easier to describe with pictures than 1000 words (And I tend to waffle and not say much). The diagrams were worth doing as now I have something to use again for other discussions. I just will have to spend some time drawing a better projectile.

 

[toodogs]

Yes, pics are valuable. To think that, for me anyhow, 15 years ago ammo concentricity was not mainstream consideration for shooters, sure wasted lots of time and ammo trying to understand why a given rifle didn't shoot like magazine articles said it should. Then I rolled my reloads in a home-made v-block with a Last Word indicator. Made a tool to bend the bent ones straighter. Remarkable, and here I am today. Link below pic is to WTS in classys.

http://www.accurateshooter.com/forum/index.php/topic,3745767.msg35852740.html#msg35852740

 

[queen_stick]

I'm still in the early stages of creating long-range match grade ammo... I have the knowledge now, so I'm left with putting all of this stuff into practice. With that said, when I measure concentricity I use the RCBS tool. I have two of them; one set up for measuring the unloaded case neck, and one setup for measuring the seated bullet. The cases come out of the chamber with less than .001" neck runout (usually zero, or very close to zero.) In my 6BR, I neck size only with a Wilson bushing die, and typically have .001" or less runout (A few cases have more runout, but typically less than .002", and are not used for record shots if more than .002"). I then measure the seated bullets, which are seated with a Wilson chamber-style die, and with .001 - .0015 neck tension. The bullet runout is usually directly related to the neck runout, but slightly exaggerated, obviously. I don't worry about it too much, and don't do anything to correct it. Less than .002" of bullet runout is ok by me, and most cases fall within that range.

I measure neck runout about .020 back from the case mouth, and I measure bullet runout where the ogive meets the bearing surface. The gun shoots a lot more accurate than I can, so I don't see any reason to take any additional steps for runout correction or more precise measurement by purchasing other tools.

I think runout is like any other process... there's a point of diminishing return. If I had to give advice, I'd say to do what works for you with minimum effort. Spend more time shooting than worrying about the reloading bench; although both are critical to create a 'full package' of accuracy.

Perhaps one day my shooting skills will exceed my current reloading process, and I'll need to make an adjustment. Until that day comes, I'll keep doing what works for me.

Walt

 

[camac]

Walt, I agree - If there is any wind, all this work we do matters not much at long range. There is no substitute for practice in those conditions. Dead calm days and closer ranges though I am glad I have put the extra effort in. Nothing beats the feeling of seeing your first 100 yd group in th "1's" or even "0's" after all the work. At the longer ranges it is very nice having the confidence in your rifle and loads - then you can only blame yourself. After all these years I am not much of a shot either. Wind and mirage are not my friends and I have trouble talking to them.
But
1) Ask any long range shooter if they would like the best accuracy possible and answer will be a definate yes.
2) Ask them how much they would pay for it - or indeed how much effort they would go to to achieve it and then you get the full range of answers. The majority will take the easiest options that give you best returns. A few will do nothing, spend nothing and "hope" it comes to them. Only a small handful of die hards go all the way.

 

[OKIE2]

The one I have is excellent, best feature is checking runout, easy to use. Must be carefull when correcting runout not to apply to much pressure – on dial indicator just equal to amount of runout you measured, i.e. .015 runout error – apply .015 to .020 to opposite side. Large errors are hard to fix IMO.

No you are not right if you have .015 thousanths
runout you only move it half that amount to make it straight.

 

[billt]

There is a view that I suscribe to that tools that 'straighten' out of true rounds are the wrong solutions to problems. If you've got excessive runout, sort the brass and/or the tools. Laurie,

York, England

I agree. I think a reloaders money would be better spent buying a set of RCBS Competition Dies, or at least the Redding Competition Bullet Seating Die, rather than fooling around trying to "bend" crooked ammunition straight with some sort of gizmo that belongs on an infomercial. High quality reloading tools like the Competition Dies manufactured by RCBS and Redding are designed to minimize bullet run out in the first place. They definitely make a difference, and are worth the money.

In machining you pay for closer tolerances. It's better to pay for a $125.00 set of precision dies to start out with, that you know will in fact reload correct ammunition, than it is to buy a $25.00 set of dies and a $100.00 tool to bend the final outcome into shape. Bill T.