I'm looking at getting a concentricity gauge and I'm wondering how important they are? Also what kind do you use?
- Thread starter hillbillydelux
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If you want a concentricity gauge, and don't mind paying for it the AccuracyOne gauge is the best there is imo.
Bullettipping.com sells them with a Mitutoyo indicator for 400$ so not cheap.
But for ease of use and consistent reading it can't be beat from my experience, the wheel turn makes it very easy to get consistent results, so no more fiddling with your fingers to apply the right amount of pressure while turning the case.And no more irradical movement of your dial when turning.
The 21stcentury gauge is also nice, more convenient for measuring ID runout of your necks, but else the accuracy one gauge is the top of the heap.
I have both of these and a Hornady gauge, and the accuracy one is my favorite by far.
How important it is to have one is up to yourself to decide, it's a tool i won't reload without anymore but each to they're own.
Besides checking neck and bullet runout.
You can also check consistency in your equipment and reloading procedure with it to some degree, and it will tell you if something is off, and how change in equipment and technique affect your result.
Reloaded for many years without one, but it depends on the goals for your ammunition.
And what you use it for.
This vid explains the accuracy one product quite well.
http://www.youtube.com/watch?v=O71oLgRqJa4
Bullettipping.com sells them with a Mitutoyo indicator for 400$ so not cheap.
But for ease of use and consistent reading it can't be beat from my experience, the wheel turn makes it very easy to get consistent results, so no more fiddling with your fingers to apply the right amount of pressure while turning the case.And no more irradical movement of your dial when turning.
The 21stcentury gauge is also nice, more convenient for measuring ID runout of your necks, but else the accuracy one gauge is the top of the heap.
I have both of these and a Hornady gauge, and the accuracy one is my favorite by far.
How important it is to have one is up to yourself to decide, it's a tool i won't reload without anymore but each to they're own.
Besides checking neck and bullet runout.
You can also check consistency in your equipment and reloading procedure with it to some degree, and it will tell you if something is off, and how change in equipment and technique affect your result.
Reloaded for many years without one, but it depends on the goals for your ammunition.
And what you use it for.
This vid explains the accuracy one product quite well.
http://www.youtube.com/watch?v=O71oLgRqJa4
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I use the sinclair model and find that it has really helped my accuracy. How much it'll help you depends upon how straight the ammo you're loading now is. If you're already loading straight ammo then the gauge will do nothing for you. If your ammo is crooked like some of mine was then it'll allow you to track down where in your reloading process you're introducing runout and correct it. Some guys buy the gauge and don't find it very useful, I use mine a lot. It's been my experience that it's impossible to build a really accurate load without controlling runout.
This is the point for me. It brings QA/QC to reloading. You can methodically work through your process step by step and check that you are getting a 'quality' result. If not you can work at it until you do.
After that the odd check to ensure that your standards are maintained is good enough or you can check every round, up to you.
Worthwhile in some applications but not in others...
One of the main causes of neck runout is locking down the decapping rod/expander button off center during die setup, the next cause would be unequal neck thickness.
I use a Redding neck thickness gauge to check the necks and would recommend the Sinclair concentricity gauge for measuring runout.
A cartridge case with unequal case wall and neck thickness will expand more on the thin side of the case and warp and become banana shaped when fired. With normal small variations in case thickness this isn't a problem and will depend on the quality of the brass.
With "both" gauges above you will be able to sort your cases and setup your dies with the minimum of induced error from the expander button, seating dies etc.
Below is my RCBS case mastering gauge and my Hornady concentricity gauge, the RCBS gauge is the Swiss Army Knife of gauges and had to be modified to get accurate runout readings and why I recommend the Sinclair gauge. The Hornady gauge is for straightening/reducing neck runout on lower quality brass with unequal neck thickness.
Below is why I recommend the Sinclair gauge, the V-blocks are painted aluminium and spinning the case wears through the paint and "into" the aluminium. This creates a lot of turning resistance and I have to grease the V-blocks to keep the case rotating freely. The metal bar and lock nut was added to keep the V-blocks from moving up and down and adding to the neck runout. The Sinclair gauge uses fixed ball bearings to rotate the case on that lock down and do not move.
One twist of the case below will tell you all you need to know about neck uniformity and a cause of runout.
I have been reloading for over 46 years and the neck gauge and runout gauge have made the biggest improvements in my reloaded ammunition. I got by for 35 years without the gauges and only reloaded for my hunting rifles and milsurp collection. "BUT" if you want to load the best possible ammunition you can then the gauges let you take the next step.
As a side note I use the Hornady gauge with lower quality brass I shoot in my AR15 rifles to get the runout below .003. With my bolt action rifles quality brass with runout at .001 or less reduces group sizes.
The type resizing dies you use, the quality of your brass, the type rifle you are shooting and the accuracy you want to achieve determines what you will get out of your gauges.
I use mine to verify that the bullets are seating straight. Tipped bullets is a major source of inaccuracy. Of course, I just got it last year, and it hasn't held be back in the previous 20. I'd say that it's not very important if you're doing everything right to begin with. They can be helpful for troubleshooting, I suppose.
I use a 21st century model and have zero complaints about anything I've bought from them.
I use a 21st century model and have zero complaints about anything I've bought from them.
I use a sinclair and like it, it allows me to check my runout throughout my reloading process. Dont get the hornandy one, I dont like it at all. Now how important is it is up to you, I always use it when sizing my brass. I've shot great groups even at distance with .003" runout on brass neck so who knows.
Could you explain why? It may be most helpful.
Two sides to this coin:
side one - Use the money saved on not buying a concentricity gauge and spend it on quality reloading tools. Like Redding Comp sizing and seating dies or Forster dies with a quality press (Redding, RCBS, Forster, ect) and good brass like Lapua. And learn to use them correctly. That way you will not need a concentricity gauge.
side two - buy one anyway, but 2 options: Only buy a quality dial indicator (no "budget indicators") and a good set of vee blocks all set on a flat surface like: a lapping block, glass, or surfaced stone like granite or marble. You will have a very quality tool with now multiple uses and will be out less money. Or buy the best premade tool you can afford. But if you do buy one it don't mean you can skimp on reloading tools
But this is just my .02
side one - Use the money saved on not buying a concentricity gauge and spend it on quality reloading tools. Like Redding Comp sizing and seating dies or Forster dies with a quality press (Redding, RCBS, Forster, ect) and good brass like Lapua. And learn to use them correctly. That way you will not need a concentricity gauge.
side two - buy one anyway, but 2 options: Only buy a quality dial indicator (no "budget indicators") and a good set of vee blocks all set on a flat surface like: a lapping block, glass, or surfaced stone like granite or marble. You will have a very quality tool with now multiple uses and will be out less money. Or buy the best premade tool you can afford. But if you do buy one it don't mean you can skimp on reloading tools
But this is just my .02
Sounds good guys thanks for all the quick responses! I do use all quality reloading equipment and don't have a huge problem with accuracy. But I do like the idea of being able to check it thanks again for all the opinions!
It's a savage model 10fcp-sr in .308
Yes, you will benefit by having a concentricity gauge to identify steps in your ammo build process that introduce runout. You will soon discover the majority of runout is attributed to non-uniform neck thickness. And, the next addition to your bench will be a neck turn tool.
I have the NECO gage.
I had a spare "last word" indicator so I can simultaneously measure runout at the bearing surface and the meplat.
20 years in the machine shop/tool & die shop (as a moldmaker) so I have some experience with metrology.
The NECO gage comes with v-blocks and other supports to measure case wall variation.
The design of the v-blocks is pretty good, anodized aluminum with very small bearing surface, very little drag.
That said, I haven't seen a marked improvement since I started paying attention to runout and taking steps to eliminate it, like turning necks and using neck bushing dies.
The jury's still out on this one, though.
For $hits & giggles I examined a box (20) of .308 FGMM 168 grain ammo.
It was appalling how much runout there was. as much as .009" TIR (total indicator reading) which is in fact only .0045" eccentric.
Despite that, the ammo grouped pretty well, averaging .8 MOA (5 shot groups, 100 yards.
I had a spare "last word" indicator so I can simultaneously measure runout at the bearing surface and the meplat.
20 years in the machine shop/tool & die shop (as a moldmaker) so I have some experience with metrology.
The NECO gage comes with v-blocks and other supports to measure case wall variation.
The design of the v-blocks is pretty good, anodized aluminum with very small bearing surface, very little drag.
That said, I haven't seen a marked improvement since I started paying attention to runout and taking steps to eliminate it, like turning necks and using neck bushing dies.
The jury's still out on this one, though.
For $hits & giggles I examined a box (20) of .308 FGMM 168 grain ammo.
It was appalling how much runout there was. as much as .009" TIR (total indicator reading) which is in fact only .0045" eccentric.
Despite that, the ammo grouped pretty well, averaging .8 MOA (5 shot groups, 100 yards.
I find this to be very interesting.
I had a Hornady unit, I was never able to repeat the readings between my Sinclair and it, the Hornady can only be used on loaded ammo, with the Sinclair type you can use it to check fired cases(indicating bad chamber job if run out exist) sized cases(bad sizing technique) and loaded cases, by checking each step you can see where run out being introduced.
You can only check runout in a case that has a bullet seated in it, you cannot check runout through your sizing process. Like above I could never get the two to line up, and I trust my Sinclair one. Also it's not advisable to try and "fix" runout by pressing on one side of the case for obvious case tension problems.
I had the Hornady one and sold it after I realized that you could only check loaded ammo and then found out that pressing on the bullet to remedy a concentricity problem probably causes more issues than it fixes. Hornady hangs their hat on this feature which no other concentricity gauge offers, for good reason.
I’m not dissing Hornady reloading products, just the concentricity tool. I find that their single stage primer pocket crimp tool is the best crimp removal tool that I’ve used.
Regardless if which one you buy, get ready to go down the rabbit hole. I've found it to be a vexing issue--I've chased the problem quite a bit over the years with different guns/dies/presses etc.
I'd also ask what your expectations are for accuracy and at what distances. the ROI on obsessing over runout might not be worth it.
I've had both the NECO and Sinclair tools, and currently use the Sinclair.
I'd also ask what your expectations are for accuracy and at what distances. the ROI on obsessing over runout might not be worth it.
I've had both the NECO and Sinclair tools, and currently use the Sinclair.
it's interesting and as with so many things, experience and objective data rule the day. likely i'm not understanding the relationships well. i was under the impression that the bore dimension was slightly tighter than the projectile. Given the bore concentricity is not a factor that the reloader can effect.
i would have imagined that even if the projectile were eccentrically located, once chambered and forced down a long tight bore, concentricity would have been optimized, the rate limiting step being the quality of the bore dimension and alignment.
i would have imagined that even if the projectile were eccentrically located, once chambered and forced down a long tight bore, concentricity would have been optimized, the rate limiting step being the quality of the bore dimension and alignment.
