Concentricity tools... Bullet run out

Jrji

Jrji

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Is anybody using Hornady's concentricity tool? I've Purchase the tool and have some serious apprehensions on it's use and how it works (after using it). When I use the tool and put the round into it I noticed that there's pressure at the tip of the bullet and at the primer end of the cartridge, because of this I don't think I'm getting an accurate reading on the actual concentricity of the bullet in relation to the pocket primer.
After using the Hornady tool my reload run out is either at zero or one thousands of an inch of run out. when I put that same cartridge on the Sinclair concentricity tool The bullet run out is extremely off from Hornady's tool (5-6 thousands of an inch). If your not familiar with the Sinclair tool theirs no pressure on either end of the cartridge giving it a better reading, Not sure what to think. Comments are appreciated.
 
The Hornady gauge will read less than half the runout of the Sinclair type gauges due to the spin axis. So don't be upset, the Hornady gauge holds the case just like a chambered round. Meaning the rear of the case is held and centered by the recessed bolt face and by the bullet in the throat.

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I recently started a thread on the Accurate Shooter Reloading Forum (link below) with a very similar question. In my case I was comparing my Bonanza runout gauge (which indexes on the bullet tip like the Hornady gauge) with the Sinclair gauge that I had just purchased. There were many good responses to my initial query that might prove helpful here.

http://forum.accurateshooter.com/threads/problems-with-sinclair-runout-gauge.3927958/
 
Jrji said:
Agreed!
Click to expand...

Don't be so quick to give up on quality gauges, a runout gauge will tell you a great deal.

If you have a runout gauge and full length resizing, a runout gauge can tell you if the expander is locked down off center and pulling the case neck off center.

And the same applies if neck sizing only with a bushing die, and the runout gauge will tell you your bushing is causing a problem.

And if you don't want to spend the money on a runout gauge I highly recommend using a Forster full length benchrest die with its high mounted floating expander.

To me the reason for reloading is to make higher quality ammunition that is better than factory ammo.
 
b72471 said:
CONCENTRICITY GAUGES; I HAVE ONE USED IT FOR A FEW YEARS THEN SET IT ASIDE, damn thing drove me crazy. The real question on these gizmos "DO THEY REALLY IMPROVE ACCURACY?".
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I still use mine, but you raise an excellent point. The case spinner has shown me numerous instances of where run-out is being introduced, and how to fix it. Great right?

I'm not so sure anymore. Here's some a couple of examples; that don't include a shread of real
science, so you've been warned :) .

My .338 Edge is a decent enough gun, BAT action, 30" Hart barrel and whatever magic Carlock came
up with. Trouble is, when initially necking up the .300 RUM brass with a tapered expander ball the loaded ammo on the first go round had crazy runout. Gnashing of teeth, sack cloth and ashes, yell at the wife and kick the dog, cry yourself to sleep crooked. Some were 17 or 18 thou out of whack. Once fire-formed they were excellent from there out. I hate wasting good barrel just seeing if the gun makes a nice banging sound, so I started using the crooked fire forming loads at my range, where at least I could have some
fun and have some clang with my bang. On a calm day the crap shoots 1/2 minute at 1/2 mile. It doesn't shoot any better with the good stuff.

Another example. I was loading up 300 .257 Weatherby for an up-coming culling trip and somewhere about the time I finished I discovered that some worn out parts on my press were causing excess runout on some cartridges and wild variations in COL. Switching presses and seating the bullets to match the shortest ones (correct length) fixed the COL issue, and rolling the cartridges separated the good from the bad. Since I don't need 4 boxes of foulers, I shot them for group at 100 and 300 meters against the "good stuff". Besides being a good way the kill a whole chilly day, I don't think
I proved s damn thing. Everything shot about the same, which is to say very well.
 
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