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Hornady or Sinclair concentricity guage
- Thread starter gonewest
- Start date
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99.5 % of the data posted on this website is unfortunately "empirical". I would love to see a double-blinded study with positive and negative controls and enough reps under numerous environmental challenges to prove to me that the time I spend performing these procedures is not wasted. Probably not going to happen, so these discussions on conjecture will likely continue. Interesting though...
One of Santa's beautiful elves (my wife) bought me a Forster Case & Cartridge Inspector tool for Christmas. I planned to do some controlled tests just to see if some of the bother is really worth the effort. Things I want to look at:
Sort cases by concentric necks ... load sorted batches and check to see if runout is transposed in kind to the finished round.
Check runout on loaded rounds ... sort and shoot and compare results.
Do the same for neck turned rounds.
Sort cases by concentric necks ... load sorted batches and check to see if runout is transposed in kind to the finished round.
Check runout on loaded rounds ... sort and shoot and compare results.
Do the same for neck turned rounds.
By the way, all of my very best groups were loads with Winchester brass, necks turned, flash holes deburred, nothing done to the primer pockets. Powder was from a measure, then trickled, one by one. Each finished round was checked in an RCBS precision mic to .001 for depth.
A top barrel maker also told me his best 600 yard group was shot from his "cull loads" that he mistakenly shot that had more runout than the rest of the loads.
So.........
A top barrel maker also told me his best 600 yard group was shot from his "cull loads" that he mistakenly shot that had more runout than the rest of the loads.
So.........
Kevin Rohrer
Well-Known Member
I'd be interested in comparing the cartridges I tested w/ my Hornady in another manufacturer's concentricity gauge. Anyone here live in NE Ohio who would like to either come to my house w/ their gauge or allow me to visit them w/ a loading block of cartridges?
Trickymissfit
Well-Known Member
did just that. A few years back a group of guys I worked with got into a heated argument of ammunition quality in their reloads (one group used Dillon stuff and the others used everything else). Then I kinda laughed at them, and they drug me into the argument. I told them to go out and load a dozen dummy loads as best they could (no powder or live primers). Then we would check the out in a Shadowgraph comparator. I setup a vee block and aligned it with a positive stop on one end. Ammo went from almost .010" runout to about .0015" TIR. It was amazing how many case bodies were not square with the base. Shoulder deminsions ran all over the place per loaded lot of rounds. I expected to see a little difference in length of the shoulder between each bunch (figuring they would be sized to fit the chamber), but not with each group of 12 rounds. The single stage presses were pretty consistent, but not always square. The multistage presses were just all over the place and usually had about .007 or more run out. (it was also amazing how many cases had bent rims on them and I had to stone the base to get rid of this). I remember seeing bent necks! And necks that looked like a camshaft! Yet most of the bullets were seated fairly strait (.005" range). My ammo showed the lowest readings, and I actually expected this. But never said it to the others. Most guys blamed the cases by having bad dies (I knew better), and others blamed it on bad seaters (I might have gone along with that a little bit). Most of the errors we saw were operator errors! As well as from built of slop in their equipment. My boss asked me to come over to his house and take a look at his setup, and I did. He was using a big orange press (thing was very heavy), and I could move the ram .003" and it looked like the shell holder mount was not square by maybe a thousandth of an inch. The following Saturday he has the frame on the shop as well as the ram. Set it up on a SIP and bored the frame for Ampco bronze bushings. While that was going on I had the ram reground strait and round. We then rebored the bushings for about .001" clearence, and requalified the die location and shell holder surfaces (threads were not exactly square, but I didn't tell him). He took it home and later brought in a half dozen rounds to check. His run out was less than 1/3rd of what it was.
gary
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Trickymissfit
Well-Known Member
rem300ultra
Well-Known Member
Add another vote for Sinclair. Had mine for 8 years.
