Doing Better - Concentricity Gauge?

[ericwh]

I'm interested in doing better. So I'm planning on doing the following:

• Get a digital scale and weight sort my brass
• Upgrade trimmer as mine sucks - not straight and pilot sometimes scars inside of necks

I was also considering buying a concentricity gauge, but I'm not sure what I would do with that data. It might tell me I have a lot of runout, but where do I go from there?

Considering upgrading dies and/or buying an expander mandrel die. Right now I have:
Hornady Match Grade Bushing die for 6.5cm - neck tension is good but I want to run something through the neck afterwards.
RCBS for .223 - giving me .003" neck tension so I'm happy with that. I know it's working the brass more than a bushing die would but I'm not that worried about that.
Since I'm happy with neck tension in both instances, is this something I would wait on until I see the results of testing runout?

Press is an old hand-me-down RCBS RC.

The other thing I'm not doing is annealing. I have a lot of brass and I haven't gotten to 3x fired on any of it. If I'm going to do that I would probably just get an annealeez.

 

[ericwh]

Bump.

Is anyone here using a concentricity gauge and what were your findings?
Did you change anything in your process/equipment to decrease runout?
Did this affect group size?

 

[wyosam]

Curious about this myself. Concentricity gauge will be here tomorrow, so I’ll see where I’m at. Still not sure what I will do with the data. I’m using quality dies on a Forster Coax with high quality brass, so I’m not sure what I will change if the numbers aren’t good. I guess it will be looking at where I’m messing them up. I’ll check fired brass, then at each step to look for places to improve I guess.


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[ericwh]

Interested to hear what you find.

Your comment about having good dies is sort of what I was thinking. If I get a gauge and find bad runout, I'll upgrade dies and that's probably it. So why not just upgrade dies and skip the gauge?

Instead of measuring runout, maybe I would be better off with Sinclairs neck sorting tool and doing some further culling of my cheap brass so I have a better starting point. Are you doing anything like that? I read that brass thickness variance can be a big cause of runout.

 

[wyosam]

In theory, the Forster gauge I ordered has the ability to measure neck thickness as well. I’m curious to see what I find with it. I’ve use a lot of Lapua, Alpha for 6 Dasher, some star line, and a little lake city 223. I’m curious to see how they compare. I really don’t know what it will gain me. I get the occasional flier both on paper, and on the chrono. They don’t typically seem to correlate at 100 yards. I think what I will do is measure concentricity and neck thickness on a batch of 50, and mark outliers in both with a sharpie. I wont make any changes to process, or do any sorting. Then I’ll see how the marked cartridges compare at the range.

Honestly, its just one more thing to tinker with. Working in healthcare the last year has me pretty burned out, and time at the bench and the range helps keep me sane.


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[wyosam]

Forum has gone crazy with duplicates

 

[wyosam]

Duplicate

 

[wyosam]

Duplicate

 

[Mosby]

I have a Neco concentricity gauge. It is helpful when I am loading for long range shooting to measure run out. I don't bother to use it anymore if I know I won't be shooting past 400 yds. Same for weighing brass and bullets. I used to neck turn my brass and weigh everything and I didn't see much of a difference in performance at shorter ranges.

I think full length resizing, deburring the neck, flash hole and cleaning the primer pocket is as important as anything. I prefer to use Lapua or Norma brass but once brass is prepared properly, I again don't notice a big difference at the range when I used Remington, Federal or Winchester.

I found that when I got rid of my RCBS rock chucker and switched to a Forster Co Ax press, my groups improved. When I put better scopes on my rifles, my groups really improved. When I started loading Barnes bullets that also helped reduce my groups. Combined I got to a certain accuracy that is sufficient for hunting(sub MOA) and allowed me to spend less time at the reloading bench on processes with marginal benefits.

 

[Lawnboi]

I’m doing the mandrel thing, and can say I definetly see a difference on Hornady 223 brass. I run a sinclair turning mandrel through. Lapua is pretty even after sizing, Hornady is all over the place, some cases require no pressure, some require quite a bit. I went the mandrel route as it seems that’s what most competition guys are running around here, and it makes sense to push the abnormalities to the outside.

I’m sizing with a Wilson bushing die (no expander) and seating on an arbor press. I’m not measuring runout yet because I don’t see what the number would give me. Instead I’m working on getting something to anneal with, and getting a better powder drop first.

 

[VernAK]

I have 3 different concentricity gauges but find myself using the Sinclair almost exclusively. I do much the same as most of the above. Buy quality brass.....I really like Alpha.......coax press improved concentricity for me as well as Redding and Forster seating dies. I resize every time and trim with Little Crow........after loading, I check for concentricity at the ogive.....rarely do I see a runout of .003 and most are <.002.........if preparing for a match, I select those <.001.........for larger caliber hunting loads, .003 to .004 is my goal.

 

[ericwh]

I’m doing the mandrel thing, and can say I definetly see a difference on Hornady 223 brass. I run a sinclair turning mandrel through. Lapua is pretty even after sizing, Hornady is all over the place, some cases require no pressure, some require quite a bit. I went the mandrel route as it seems that’s what most competition guys are running around here, and it makes sense to push the abnormalities to the outside.

I’m sizing with a Wilson bushing die (no expander) and seating on an arbor press. I’m not measuring runout yet because I don’t see what the number would give me. Instead I’m working on getting something to anneal with, and getting a better powder drop first.

Other than the quality of manufacture and/or "floating"/"self-centering", I'm still not clear how an expander mandrel/die is any different than using the expander "ball" in your Wilson bushing die?

Bad thing is forster dies are pretty well out of stock and so are the sinclair expander dies.

KM expander dies are in stock and not too expensive - seems like the same concept as the sinclair expander.

 

[ericwh]

... I resize every time and trim with Little Crow...

Trimmer is on the upgrade list. You are using your little crow in a drill?

I have visible runout in my drill chuck. Since the Little Crow style trimmers index on the body I'm not sure if my drill runout would cause a problem or not. Any input on that?

I was considering the lyman case trim xpress which indexes on the body but is a self-contained/powered unit to avoid using the drill altogether.

 

[Lawnboi]

Other than the quality of manufacture and/or "floating"/"self-centering", I'm still not clear how an expander mandrel/die is any different than using the expander "ball" in your Wilson bushing die?

Bad thing is forster dies are pretty well out of stock and so are the sinclair expander dies.

KM expander dies are in stock and not too expensive - seems like the same concept as the sinclair expander.

My Wilson sizer does not have an expander ball. I stayed away from expander balls for the very reason people say they induce runout.

I have sinclair, but have looked into k&m. I should have gotten the carbide mandrels. If they are available I’d get them over steel.

21st century also makes mandrels.

I only use the expanding mandrel on new brass. Turning mandrel is used on fired.

And drill runout was the reason I got rid of my giraud tri way. I also have a Wilson trimmer that’s slow, but easy to be very very precise

 

[JJMoody]

I’d skip the concentricity jazz and stick with the mandrel for setting neck tension. What I’ve found is Good quality bushing dies, good quality brass and consistent neck tension is about all I’m capable of measuring the benefit from. Es/sd has shrunk way down just by doing the above. You already need good brass and dies-they’ll eventually pay for themselves. The mandrel expander was MY ticket for increased precision.

 

[wyosam]

So I measured a bunch I have loaded, and a few more as I loaded them. Most of my already loaded rounds were quite good- in the
The ones I loaded tonight, I found that the ones I seated part way, spun the case a partial turn, then finished seating were all under .003, most less than 002. I used to do that with cheaper dies and noticed a difference on paper, but hoped higher end dies eliminated the need. I guess not. I spot checked some cases before I loaded, and all I checked were

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[ericwh]

On my end I weighed some brass. I know many people say this measurement is inconsequential.

I also measured the neck thickness in 4 places using my calipers (not the best tool I know).

I have been using PMC brass for .223:
Avg Weight: 92.28
Weight ES: 1.4
Weight SD: .5

Average Neck thickness variation (in thousandths): 1.5
NTV ES: 2
NTV SD: 1.8


I also had some Hornady on hand:
Avg Weight: 92.65
Weight ES: 5.5
Weight SD: 1.3

Average Neck thickness variation: 1.2
NTV ES: 1
NTV SD: .4

Regarding neck thickness, in this article (http://www.mssblog.com/2016/04/29/case-segregation-neck-wall-thickness/) the author claims "I do know that when Hornady tested this at 200 yards (on their indoor range), they found that variation in wall thickness of 13% had a significant influence on group sizes;"

Most of the stuff I've read says case neck thickness variation will cause concentricity issues. In my mind, this would also cause a neck tension issue? And my ES and SD in this cartridge has always been worse than my other cartridge.

I found it interesting that the Hornady was significantly more consistent in case neck thickness but significantly less consistent in case weight. I think the cntv is more effective but I'm not crazy about what I found for either of these.

I see Norma in stock for $.40/pc and Lapua for $.78/pc...

 

[Lawnboi]

You should be able to get Lapua for around .60 per piece. Mid south has it right now

 

[ericwh]

You should be able to get Lapua for around .60 per piece. Mid south has it right now

How did I miss that? I thought I looked all over. Good looking out.

 

[hereinaz]

Get Redding or Forster match dies.
Use Lapua brass or one of the US custom brass like Alpha or Peterson.
Use a mandrel not the expander ball.
Bump shoulders .002.
Get a quality scale and be precise with powder.
Henderson trimmer.

I know many guys who that is all they do any more and get low ES. Its all I do and my ES stays under 20.

I don't worry about concentricity at all any more. Sold my gauge. I seat bullets halfway and then spin it 180 to seat all the way. It has very little to do with precision compared to other things.

Weighing brass is a useless and meaningless endeavor. Check water capacity.

The mandrel is in the entire neck at once it finishes the stroke. The ball slides through the neck at varying speeds and isn't pressing the whole neck out at once, which is likely one cause for inconsistency of neck sizing with the ball expander.

Go watch Eric Cortina's videos on YouTube.

There is FAR too much garbage info out there and crazy gear that isn't needed. Don't get sucked into questionable methods like weighing cases when it clearly doesn't correlate to case capacity, which it is supposed to measure.