Hornady Concentricity Gauge

[RN]

Ok..I went to Bass Pro today and it seems that I cant leave without something new for the bench. I have been eyeing the Hornady Concentricity Gauge for awhile as I like how it not only detects bullet runout but also corrects it. I have to say that it works as described and after some playing with it I can get runout close to .0005..Almost perfect so I am thrilled the product. What's funny is that I had to use factory ammo to get some bad examples of runout!! Says a lot for my Forster Dies and press!! Some of my ammo had some minor runout but all was quickly corrected with this tool..

Now, what is that really doing for me? I can see the bullet runout disappear so I know that's working but how does it improve accuracy? Is this basically a short cut when you don't spend the time neck turning? I am ok with that if so. I would actually think that's a good idea by Hornady.

So, enlighten me guys!! What do I have here and is it useful?

 

[jwrowland77]

It's supposed to improve accuracy by letting the bullet start more in line with the barrel instead of it skewed to one side or the other.

I had thought about getting one but just haven't yet. Still one the fence about it. I bought Lee collet neck dies first, now neck turning and annealing and saw improvement doing those, so haven't bought the concentricity tool.....yet. Lol

 

[RN]

Yet is the key word..lol..Well, I can attest that is a nice piece of equipment(Typical Hornady) and does exactly what it says it will do. Now, will I see theoretical improvements even though I do not neck turn? Or, is this something that will only work in combination with neck turning.. I have no idea but in reviews of the product people seem to really achieving some improvement using this alone..

 

[jwrowland77]

Be sure to post range report after testing it.

I'm all for squeezing out that last bit of accuracy out of my match ammo. Lol

 

[RN]

Will do..I am going to have to shoot Factory ammo to get a "bad" control group as this gauge tells me its way off.. American Eagle .001-.007, Independence .002-.006 .223 were way off and that's only testing about 15 rounds each. My loaded ammo is looking really nice but now I can even tweak it further.. More fun at the bench!!

 

[twofifty]

It might be interesting to measure and see which bullet seating strategies result in the least runout, and by how much...

 

[Offfhand]

Curious here. When measuring bullet runout, at what place on the bullet do you take the runout reading?

 

[RAT807]

This tool has helped me with my loads and now they are below .002 runout. I have found that ammo in battle packs or sealed plastic bags (not my reloads) is a no-no. Major runout on these rounds. I've shot a few groups with these rounds and the groupings were not impressive. I also took 10 of the same batch and using the Hornady gauge was able to reduce the runout below .002. These 10 had a much better grouping but the neck tension was not consistent. After checking the runout on the rest of the batch, any round more than .007 I pulled the bullet and ran the case through a neck sizer die and reseated the bullet. The group I shot with these had the best grouping. So if your rounds are measuring runout at or below .004, you're doing good. Any more runout and you need to step up your reloading game.

 

[Reloadron]

I don't need no stinkin gauges because my reloads has real good run outs and concentricities!



They choot just fine in my gunz.

RN, I am beginning to worry about you. Pretty soon I see a possible intervention in your future. You are beginning to show OCD symptoms in your reloading. I am sure working as a medical field professional you can see this happening.

On a more serious note gauges like this can be a good thing and there is no limit to how many are out there to aid the hand loader in their quest to make perfect ammunition. Here is a link to a previous THR thread on the subject of bullet runout and concentricity. It may be a good read for those curious about this stuff.

Since a big number for bullet runout is a bad thing other than nudging our bullet around in a gauge to get it true to a center line we can begin correcting the problem before the cartridge is ever loaded.

Steps to Minimize Bullet Run-Out is a very good read on the subject from our friends at Sinclair who make some really nice stuff aimed at the serious shooter. Starting at the beginning with Case Prep Steps to Minimize Run-Out and moving along through Sizing Steps to Minimize Run-Out, Seating Steps to Minimize Run-Out, and finally Bullet Straightening Tools. Interesting stuff.

I have a question though. Look at a 308 Winchester SAAMI specification for both cartridge and chamber. The SAAMI drawings clearly show the MAXIMUM CARTRIDGE / MINIMUM CHAMBER specifications. This is why the cartridge when correctly sized actually fits in the chamber. Just look at the numbers and tolerances in the drawing. So here is my question.

Most bench rest shooters and long range match shooters will tell you they want to keep the TIR (Total Indicator Runout) to within 0.002". Sounds good to me. When I chamber a round my bolt face is square against my cartridge head with my chambered round. Well it should be square shouldn't it? My bolt face is true right? My locking lugs on the bolt are true aren't they? Unless my bolt face and bolt lugs have been lapped and unless I have checked them using Dykem Blue Layout Fluid I really don't know what I have. Not to mention the chamber tolerances? Do I really know what my chamber dimensions are? So when I put my perfectly trued loaded cartridge in my rifle what can I expect? Does freebore or bullet jump matter?

Every part of the chain is only as strong as the weakest link.

Ron