Concentricity Gauge, Yeah or nay.

burnaby

burnaby

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http://bulletin.accurateshooter.com/2016/05/bullet-concentricity-basics-what-you-need-to-know/
http://www.sinclairintl.com/.aspx/lid=16572/GunTechdetail/Bullet-Concentricity-Related-Issues?&avad=avant&aid=34931&cm_mmc=affiliate-_-Itwine-_-Avantlink-_-Custom+Link

Just finished reading this article on bullet concentricity, got me thinking maybe time to get one along with thickness gauge. Already do all the other case prep steps, cartridge looks concentric eyeballing it rolling on flat surface (cast iron table saw).

Question is how important is a Concentricity Gauge. A Must have tool or will sit in some box on the shelf.


Top two picks flavoring 21st which is more than double the $$$ with the wheel. (rest of my case prep is 21st). Likely cry once with the 21st with wheel that looks easiest for accurate, repeatable readings.

Concentricity Gauge w/wheel, 21st Century
http://www.xxicsi.com/concentricity-gauge.html

Sinclair
http://www.brownells.com/reloading/measuring-tools/concentricity-gauges/sinclair-concentricity-gauge-prod37479.aspx
 
I would buy the two gauges below, the Redding neck thickness gauge tells you about the quality of your brass meaning thickness uniformity.

Redding Case Neck Concentricity Gage
http://ads.midwayusa.com/product/311160/redding-case-neck-concentricity-gage?cm_mmc=pf_ci_connexity-_-Reloading+-+Metallic+Reloading+Equipment+%28Not+Presses%29-_-Redding-_-311160

The concentricity gauge below is the best bang for the buck for setting up your dies and checking between steps to see where your runout problems start.


SINCLAIR CONCENTRICITY GAUGE
http://www.brownells.com/reloading/measuring-tools/concentricity-gauges/sinclair-concentricity-gauge-with-dial-indicator-sku749007305-37479-70547.aspx?cm_mmc=cse-_-Itwine-_-shopzilla-_-Sinclair%20Concentricity%20Gauge&gdftrk=gdfV21820_a_7c187_a_7c7313_a_7c749007305_d_749007271_d_20544

In the 1973 Speer No.9 Manual there was a chapter "Reloading for Benchrest Accuracy" it and it stated the main cause of neck runout was caused buy locking the expander down off center.

The Forster full length benchrest dies out of all the different types of dies I own produce cases with the least amount of neck runout.

forster%20cutaway_zpsz9ed4htd.jpg


The high mounted floating expander enters the case neck when the neck is held and centered in the die. And can not pull your necks off canter and induce neck runout. You can adjust many of the RCBS dies the same way and place a rubber o-ring under the spindle lock nut. Or buy the carbide floating expanders for redding dies and adjust the same way.

Below a RCBS die equipped with a Forster expander and spindle assembly that greatly reduced the dies runout.

IMG_2140_zpsea657d9e.jpg


You asked about runout gauges and finding the cause of your runout and how to fix it is important. Meaning you need quality brass and to have a die that does not pull your necks off center.

I have the RCBS case mastering gauge and the Hornady concentricity gauge. The problem with the RCBS gauge is your are rotating the case in aluminum V-blocks. And over time the paint wears off and you are trying to rotate the case on the bare aluminum which creates drag. The Sinclair concentricity gauge has four ball bearings the case rotates on and it will be my next gauge.

runout003_zpsd19b7cc3.jpg


The Hornady gauge above in the left of the photo holds the case the same way it is held in your chamber with a full length resized case and measures off the centerline of the case. The other type gauges rotate the case on the outside of the case body and will read twice the runout. Meaning quality brass with uniform case wall thickness will give lower runout readings.

NOTE: The U.S. military considers ammunition with .003 or less bullet runout to be match grade ammunition.
 
Last edited:
Using Lapua brass. Went to 260Rem instead of 6.5CM just for Lapua brass.
Lee Collet die
Redding body die
Forester or Wilson die
  • Like the Wilson die with mini arbor for better feel on seating tension.
  • Like the Forester for ease of half seating, 1/4 turn on brass, full seating. Last batch of 308 all seated <+-1 thous base to ogive.


Without a gauge don't know if there is a runout problem. Looks like only way to find out is to get a gauge.
bigedp51 said:
...
You asked about runout gauges and finding the cause of your runout and how to fix it is important. Meaning you need quality brass and to have a die that does not pull your necks off center.
Click to expand...
 
burnaby said:
Without a gauge don't know if there is a runout problem. Looks like only way to find out is to get a gauge.
Click to expand...

I have been reloading for over 47 years and didn't know how bad some of my reloaded ammo was until I got gauges.

Below is a average Remington .223 case with .004 neck thickness variation, these type cases are used for blasting ammo in my AR15 rifles. And this gauge tell me more about the quality of the brass and what is causing the runout than any other gauge. These type cases warp when fired and you end up with a banana shaped case that shoots much larger groups. (blasting ammo)

Below .004 neck thickness variation and some of these Remington cases had over .008 neck thickness variation. Meaning quality cases make the biggest difference in runout and group size.

IMG_2136_zps079ece9b.jpg


IMG_2137_zps66bcfc13.jpg
 
emerson said:
Precision? You have to eliminate the variables. Hunting, no required IMHO.
Click to expand...

Correct if your hunting grizzly bears, moose or Tyrannosaurus Rex in BC but if your shooting prairie dogs at 200-300 yards in Alberta you need better ammo.

But if you still miss the target just don't tell anyone you have gauges so you have a excuse for missing. ;)
 
The Hornady concentricity gauge also allows you to correct for runout. Personally, I would find it depressing to know that my rounds weren't concentric, but then not be able to anything about it! Also corrects factory ammo, which is cool.

There's an add-on Kit which I just received that converts the Hornady gauge into a case neck thickness gauge, and it works well.

Check out Hornadyloader's YouTube videos on these tools...very informative!
 
^ Issues with Hornady concentricity gauge is:
  • Loaded rounds only
  • Correcting runouts by force on a loaded round can not be good for neck tension. Go through hell to neck turn and perfect mandrel/bushing for 1-2 thous neck tension. Correction is a cure, we want prevention.
 
The 21st will measure the INSIDE of the case neck, not just the OUTSIDE.

http://bulletin.accurateshooter.com/2011/12/21st-centurys-impressive-new-concentricity-gauge/
21congauge02.jpg

bigedp51 said:
...

I have the RCBS case mastering gauge and the Hornady concentricity gauge. The problem with the RCBS gauge is your are rotating the case in aluminum V-blocks. And over time the paint wears off and you are trying to rotate the case on the bare aluminum which creates drag. The Sinclair concentricity gauge has four ball bearings the case rotates on and it will be my next gauge.

runout003_zpsd19b7cc3.jpg


The Hornady gauge above in the left of the photo holds the case the same way it is held in your chamber with a full length resized case and measures off the centerline of the case. The other type gauges rotate the case on the outside of the case body and will read twice the runout. Meaning quality brass with uniform case wall thickness will give lower runout readings.

NOTE: The U.S. military considers ammunition with .003 or less bullet runout to be match grade ammunition.
Click to expand...
 
The Sinclair gauge on sale is tempting.
BUT the 21st with the i/s measure and wheel is certainly the cry once.

What kind of runouts are you getting?
Gunneegoogoo said:
Sinclair concentricity and neck thickness.....

I do wish I had the wheel that the 21st offers on the concentricity....
Click to expand...
 
You know, it's funny - I started reading this thread because I picked up a metric ####ton of Lake City .308 brass(On Biged's recommendation I might add). I have begun to process it, and visibly noticed what I'd consider big differences in neck thickness in some of the cases from one side to the other, IE one side way fatter than the other. Now, a lot of times I read entire threads without looking at usernames, and I was reading this one and thought to myself, gee, this one sure sounds just like BigedP51!!
And then I realized, you know when you're reading one of his posts when you notice yourself scrolling down,






Down










Down....

Lol!

Not poking fun Ed, as I do thoroughly enjoy every post.
Have to get a handle on it usually, but that's normal for the high growth curve info for which you are so abundantly wealthy.
 
TedNugent said:
You know, it's funny - I started reading this thread because I picked up a metric ####ton of Lake City .308 brass(On Biged's recommendation I might add). I have begun to process it, and visibly noticed what I'd consider big differences in neck thickness in some of the cases from one side to the other, IE one side way fatter than the other. Now, a lot of times I read entire threads without looking at usernames, and I was reading this one and thought to myself, gee, this one sure sounds just like BigedP51!!
And then I realized, you know when you're reading one of his posts when you notice yourself scrolling down,






Down










Down....

Lol!

Not poking fun Ed, as I do thoroughly enjoy every post.
Have to get a handle on it usually, but that's normal for the high growth curve info for which you are so abundantly wealthy.
Click to expand...

I use a lot of LC brass myself mainly for my M14 and AR10 it's tough brass , perfect for semi auto. I've never checked runout and I don't know how much of a difference it's going to make in accuracy as my SDs are in the single digits already. For LC brass I had Forster hone the neck area of the die so I get 3-4 bullet tension so crimp is not needed.
 
burnaby said:
The Sinclair gauge on sale is tempting.
BUT the 21st with the i/s measure and wheel is certainly the cry once.

What kind of runouts are you getting?
Click to expand...

My 6.5x47 brass out of my Redding type S and Redding seater was insanely good - .001 or less. I'm just getting going with the Redding type S and Forster seater combo, so I'll have to let you know on that....
 
Dear TedNugent

I like posting photos and drawings because my two dyslexic typing fingers get tired, and a pictured is worth a thousand words.

Besides I only know the Columbus method of typing.................discover the key and land on it. ;)

4186.overkill.jpg-550x0_zpsymqkumeb.jpg


overkill%20wusses_zpsooi3vzta.jpg
 
Noticeable difference in neck turning reg and match 308s for Fed, Hornady, Rem, Win. Feds turn out best with ~60% surface needed to be trim. One of the others requires 90%+.
Got Lapua, barely needed any turning. Buy only Lapua for consistency and more reloads; ends up being cheaper.
TedNugent said:
You know, it's funny - I started reading this thread because I picked up a metric ####ton of Lake City .308 brass(On Biged's recommendation I might add). I have begun to process it, and visibly noticed what I'd consider big differences in neck thickness in some of the cases from one side to the other, IE one side way fatter than the other. Now, a lot of times I read entire threads without looking at usernames, and I was reading this one and thought to myself, gee, this one sure sounds just like BigedP51!!
And then I realized, you know when you're reading one of his posts when you notice yourself scrolling down,
Down
Down....
Lol!

Not poking fun Ed, as I do thoroughly enjoy every post.
Have to get a handle on it usually, but that's normal for the high growth curve info for which you are so abundantly wealthy.
Click to expand...
 
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