Hornady Concentricity Comparator/Corrector.
- Thread starter Mikem
- Start date
Sray53TXTN
Silver $$ Contributor
I have on and really like it. It ensures my bullets have zero run out and I have noticed my groups tighten up as well. Got mine from Graf's when they had them. I like mine!
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.
I dont have mine yet, but have read up on them.
After you determine the total runout, rotate the brass to its lowest reading, on the dial indicator, and remember the amount of total runout. Then you turn a screw inwards on the front, with a plastic end on it, opposite the dial indicator. And it will push on the bullet next to the case neck, removing the runout. (Remember the round is held tight at its case head, and bullet tip) You can see how far you moved the bullet and case neck back, by watching the dial indicator. And stop turning when its at half the amount of the total runout. And it should be vary close.
Mike.
After you determine the total runout, rotate the brass to its lowest reading, on the dial indicator, and remember the amount of total runout. Then you turn a screw inwards on the front, with a plastic end on it, opposite the dial indicator. And it will push on the bullet next to the case neck, removing the runout. (Remember the round is held tight at its case head, and bullet tip) You can see how far you moved the bullet and case neck back, by watching the dial indicator. And stop turning when its at half the amount of the total runout. And it should be vary close.
Mike.
There is a review of this tool in the new issue of Precision Shooting. As I see it, there is no way to check concentricity of necks before loading or before resizing. That is the best way to cull out erratic necks.
I had a Bersin tool and sold it. Forcing the bullet to one side has to bend the neck. After it is fired in the chamber, the neck should straighten and return to its original shape. However,if the case is inherently banana shaped, it will never be straight again.
I had a Bersin tool and sold it. Forcing the bullet to one side has to bend the neck. After it is fired in the chamber, the neck should straighten and return to its original shape. However,if the case is inherently banana shaped, it will never be straight again.
I have both the Hornady tool and the Bersin tool. Your question perplexed me, so I measured 10 cases loaded with 100g SII in my .25-06 case. Here are my results.
Hornady Bersin
0.0015 - 0.0072
0.002 - 0.0036
0.0015 - 0.0092
0.001 - 0.0032
0.001 - 0.0036
0.0005 - 0.0048
0.000 - 0.0068
0.000 - 0.0056
0.001 - 0.0016
0.0005 - 0.002
I corrected with the Bersin tool and this was what I got:
Hornady Bersin
0.001 - 0.0008
0.0015 - 0.0004
0.001 - 0.0004
0.001 - 0.0012
0.001 - 0.0008
0.001 - 0.0012
0.001 - 0.0008
0.001 - 0.0012
0.001 - 0.0008
0.001 - 0.0012
So I tend to think the Hornady tool doesnt do a great job. I have played with it quite a bit, but havent been able to get it to match up to the Bersin. I know the Bersin is expensive, but it does what I need it to do. If you look at the corrected ammo, I cant explain my misses on concentricity.
Hope this helps.
Hornady Bersin
0.0015 - 0.0072
0.002 - 0.0036
0.0015 - 0.0092
0.001 - 0.0032
0.001 - 0.0036
0.0005 - 0.0048
0.000 - 0.0068
0.000 - 0.0056
0.001 - 0.0016
0.0005 - 0.002
I corrected with the Bersin tool and this was what I got:
Hornady Bersin
0.001 - 0.0008
0.0015 - 0.0004
0.001 - 0.0004
0.001 - 0.0012
0.001 - 0.0008
0.001 - 0.0012
0.001 - 0.0008
0.001 - 0.0012
0.001 - 0.0008
0.001 - 0.0012
So I tend to think the Hornady tool doesnt do a great job. I have played with it quite a bit, but havent been able to get it to match up to the Bersin. I know the Bersin is expensive, but it does what I need it to do. If you look at the corrected ammo, I cant explain my misses on concentricity.
Hope this helps.
After reading numerous posts about Concentricity (neck runout) I have found its vary hard to compare someone else's reading with mine, or yours. As there's no standard place on the neck or bullet, or even the method to take thees reading.
The Hornady tool pictured above holds the case at both ends, and you take the reading at the center of the neck.
The gauge I built holds the case in two V blocks, one in the base extractor grove, and the other about 1/4" below the start of the shoulder. This cantilevers the shoulder, neck and bullet out off one V block, and I think I would get a higher reading than the same case taken in the Hornady tool above.
I normally take my BR case reading when there loaded, and have the ball of the dial indicator just below the bullets meplet, (a worst case scenario) so it exaggerates the numbers, to make my correcting easier, and more accurate. If I read .002 in the center of the neck, it will read, .006 out at the meplet.
I would suggest you not try to compare your numbers with others, as the reading can vary greatly from one method to another, and you might not be as bad off as you first might think.
When I first started reloading, 44 years ago, all we did was role the loaded rounds on a flat table top, and watch the meplet wobble.
Mike.
The Hornady tool pictured above holds the case at both ends, and you take the reading at the center of the neck.
The gauge I built holds the case in two V blocks, one in the base extractor grove, and the other about 1/4" below the start of the shoulder. This cantilevers the shoulder, neck and bullet out off one V block, and I think I would get a higher reading than the same case taken in the Hornady tool above.
I normally take my BR case reading when there loaded, and have the ball of the dial indicator just below the bullets meplet, (a worst case scenario) so it exaggerates the numbers, to make my correcting easier, and more accurate. If I read .002 in the center of the neck, it will read, .006 out at the meplet.
I would suggest you not try to compare your numbers with others, as the reading can vary greatly from one method to another, and you might not be as bad off as you first might think.
When I first started reloading, 44 years ago, all we did was role the loaded rounds on a flat table top, and watch the meplet wobble.
Mike.
Mike,
If it matters, I measured the cases above at the same place on the bullet. I actually marked the bullets so that I could reproduce the same position on the bullet each time/machine. The absolute numbers that I got may not matter to you, but the differences between the two measuring devices should. That was my point, I believe the Bersin over the Hornady device.
If it matters, I measured the cases above at the same place on the bullet. I actually marked the bullets so that I could reproduce the same position on the bullet each time/machine. The absolute numbers that I got may not matter to you, but the differences between the two measuring devices should. That was my point, I believe the Bersin over the Hornady device.
I finally got this tool. I won't have time for awhile anyway to work with it much, but I did get it out of the box and noticed that the spring loaded end has quite a bit of play in it and that I can't spin a round in it without that end turning in the fixture and when I hold the ball to keep it from turning like the directions say I can change the reading by the amount of pressure I put on it. It doesn't seem right to me, did I get a bad one?
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.
The guy who used to import the (very expensive) Bersin device into the UK tried to persuade one of the country's top benchrest shooters, who is also a shooting writer, to review it in one of our shooting magazines. To cut a long story short, he wouldn't and they had such a big falling out, I don't think they've ever spoken again!
Laurie,
York, England
The guy who used to import the (very expensive) Bersin device into the UK tried to persuade one of the country's top benchrest shooters, who is also a shooting writer, to review it in one of our shooting magazines. To cut a long story short, he wouldn't and they had such a big falling out, I don't think they've ever spoken again!
Laurie,
York, England
I agree with the thought it is always BEST to start with a "straight shell" and work on the other tips to keep it straight. Bend it out and back again is very unlikely to give as good a result although no doubt it could "improve" a "bad" one. Anyone who has bent an arrow will know what I mean.
Similarly, try and straighten a steel rod - you can't hold each end of a bent rod and push it back in the middle to get it dead straight again. You can't even push it at several spots. It requires many small steps along the length of the rod and definately not just holding it at the tips.
HOWEVER in saying this, Shells are slightly different in that most of the "bending" comes in a relatively small zone at base of neck so a reasonable result can be achieved - but surely never as good as "new". BUT nevertheless handy for semi recovering those "bent" ones even if they become your "sighters" or varmint rounds.
Also worth noting just because you correct "runout" in one point doesn't mean you have down the entire length. You can have a big wobble in between the points and still have it correct at one. It might read good on the gauge but neck might not be concentric with shoulder. The shoulder would then push across in chamber anyway. Can someone that has one though please put a few "straightened" shells back into a v block runout gauging tool and measure several points along the bullet, neck and shoulder after it shows "straight" in the hornady??
Similarly, try and straighten a steel rod - you can't hold each end of a bent rod and push it back in the middle to get it dead straight again. You can't even push it at several spots. It requires many small steps along the length of the rod and definately not just holding it at the tips.
HOWEVER in saying this, Shells are slightly different in that most of the "bending" comes in a relatively small zone at base of neck so a reasonable result can be achieved - but surely never as good as "new". BUT nevertheless handy for semi recovering those "bent" ones even if they become your "sighters" or varmint rounds.
Also worth noting just because you correct "runout" in one point doesn't mean you have down the entire length. You can have a big wobble in between the points and still have it correct at one. It might read good on the gauge but neck might not be concentric with shoulder. The shoulder would then push across in chamber anyway. Can someone that has one though please put a few "straightened" shells back into a v block runout gauging tool and measure several points along the bullet, neck and shoulder after it shows "straight" in the hornady??
camac: I took one of the worst examples of loaded round runout, ( a newly formed Lapua 220 Russian to 6ppc), I could find ( 1 round out of 20), and using my Sinclair coincintricity gauge it showed .007", the reading taken on the bullet ogive where it would contact the leade. Took the same ctg. and put it into the Hornady tool, and it showed a runout of .0015", with the dial pointer at the same location on the bullet.
Exactly - big difference between measuring runout using head and shoulder of cartridge (and these generally do more aligning shell in chamber than neck as they are stronger. - unless FL sizing of course). Just because the neck or ogive shows no runout with tip and base doesn't mean same with shoulder!! The reason the v blocks work so well is they measure from two of the most important (and strongest) areas on the shell- you can then also move your dial gauge to neck, ogive, tip etc to have an idea of what is going on. Those that do this will know you can take a cartridge with a few thou neck runout, move dial gauge to ogive or near tip, push tip "straight" so no runout there but then go back to neck again - still runout shows at neck. Is this any better?? I doubt it.
Well camac, is it any better? It makes me feel better, if nothing else.
When the seller gets off the pot, and ships my Hornady tool, ill have two testers, the Hornady and my V block unit, so I can do some comparing.
I do agree with whoever it was that said, " were treating the symptom and not the cause".
I would love to have every case straight, right out of the Lapua box, then I wouldn't need either unit, assuming my dies dont impart any runout. (Big Assumption There)
And I haven't run any tests to see just how much runout effects the POI on the paper, or compared naturally straight case accuracy, with hand straightened cases. But maybe someday ill get around to it, just dont hold your breath.
So much to do, and so little time to do it. 45 years ago, I thought this reloading business would be simple, but look at the can of worms we have here, and this is just one topic.
Laurie, can I subscribe? Your not keeping that view on your side of the pond only, are you? Because it makes a lot of sense, all the way over hear, depending on the % that are straight.
Mike.
When the seller gets off the pot, and ships my Hornady tool, ill have two testers, the Hornady and my V block unit, so I can do some comparing.
I do agree with whoever it was that said, " were treating the symptom and not the cause".
I would love to have every case straight, right out of the Lapua box, then I wouldn't need either unit, assuming my dies dont impart any runout. (Big Assumption There)
And I haven't run any tests to see just how much runout effects the POI on the paper, or compared naturally straight case accuracy, with hand straightened cases. But maybe someday ill get around to it, just dont hold your breath.
So much to do, and so little time to do it. 45 years ago, I thought this reloading business would be simple, but look at the can of worms we have here, and this is just one topic.
Laurie, can I subscribe? Your not keeping that view on your side of the pond only, are you? Because it makes a lot of sense, all the way over hear, depending on the % that are straight.
Mike.
Sorry Mikem, I should have qualified my "is it any better" statement I was waffling my own argument around in circles a bit and actually referred to a hand straighten - this system is better - But the comparison should be made from straightened to a straight case from the start. In fact I do personally think a straightened case could be better than the original bent one, just not as good as a straight one from start (although occasionally they might get close) I also actually agree totally in tools like this have a place in the reloading cupboard. No one I know gets every shell straight all the time. As you correctly pointed out - brass straight out of the box has runout. It is one of my personal "issues" with having to fireform brass in barrel burning chambers to get them straight - I hate it. I either go to the point of fireforming in old barrels, or I try and "straighten" them out of the box (the necks anyway) - e.g. 6.5mm - I expand them up to .270 with expander mandrel, neck turn at this size, and back through a FL sizer with expander ball removed and neck honed to my correct neck tension. By putting through this system at the start, the shells have very little neck runout before firing - still doesn't match the chamber yet though but reasonable in a nice tight chamber.
It would be great to see some runout measurements down the length in a few spots thanks.
ONE OTHER ISSUE THOUGH - what about neck tension - surely this messes with it??? Straightening any other way does.
It would be great to see some runout measurements down the length in a few spots thanks.
ONE OTHER ISSUE THOUGH - what about neck tension - surely this messes with it??? Straightening any other way does.
camac and mikem... I'm not trying to distract you discussion, which is very informative, but I have a few questions about this tool.
When I measure run-out on a v-block, the case simply sits on the V-block. The bullet will simply rotate freely as the case is spun in the block.
This tool holds the case at BOTH ends; the case head and the bullet meplat (I don't know that it's at those two points exactly, but that's what it looks like in the pictures). Is there any pressure between those two points of contact? If the meplat is NOT trimmed the same on each bullet, wouldn't that cause inaccuracies in the measurement? If the end holding the bullet does not hit the meplat, and grabs some point on the ogive, then bullets that are not sorted by base-to-ogive (bearing surface length) will give inaccurate results.
Another question I have is regards to the ends of the tool that hold the cartridge. If those two points are eccentric, then is it possible to read run-out that is not in the case, but is being caused by the tool its self?.
Along with the question above about pressure (pressing in on both ends of the cartridge). If the ends of the tool are concentric, and the case is not. When pressure is applied on both ends of the case when placed in the tool, then could the run-out be exaggerated?
Walt
When I measure run-out on a v-block, the case simply sits on the V-block. The bullet will simply rotate freely as the case is spun in the block.
This tool holds the case at BOTH ends; the case head and the bullet meplat (I don't know that it's at those two points exactly, but that's what it looks like in the pictures). Is there any pressure between those two points of contact? If the meplat is NOT trimmed the same on each bullet, wouldn't that cause inaccuracies in the measurement? If the end holding the bullet does not hit the meplat, and grabs some point on the ogive, then bullets that are not sorted by base-to-ogive (bearing surface length) will give inaccurate results.
Another question I have is regards to the ends of the tool that hold the cartridge. If those two points are eccentric, then is it possible to read run-out that is not in the case, but is being caused by the tool its self?.
Along with the question above about pressure (pressing in on both ends of the cartridge). If the ends of the tool are concentric, and the case is not. When pressure is applied on both ends of the case when placed in the tool, then could the run-out be exaggerated?
Walt
Walt, I do not have one so am probably speaking a little out of turn here but what you say sounds correct to me. If the holder trys to grab the tip or Meplat area somehow then it would be almost impossible to get an accurate "centre" (talking lathe talk).
BUT if it holds the bullet in a collar a little further up then that would work effectively like a V block if same pressure held on one side (maybe by spring in dial gauge??. V Blocks only work if the shell is "round" at the point of V Block. We tend to assume bullets are fairly round. They are made to pretty exacting specifications in that department (not always bearing surface or meplat though). Testing roundness at V block is easy - just put the dial gauge on top of shell at each V block and rotate - but here it is a bit more difficult to measure the "roundness" of bullet at a sloping point between ogive and tip- but same principles would apply - (anyone want to try??).
BUT if it holds the bullet in a collar a little further up then that would work effectively like a V block if same pressure held on one side (maybe by spring in dial gauge??. V Blocks only work if the shell is "round" at the point of V Block. We tend to assume bullets are fairly round. They are made to pretty exacting specifications in that department (not always bearing surface or meplat though). Testing roundness at V block is easy - just put the dial gauge on top of shell at each V block and rotate - but here it is a bit more difficult to measure the "roundness" of bullet at a sloping point between ogive and tip- but same principles would apply - (anyone want to try??).
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