Concentricity gauge?
- Thread starter Wingzero
- Start date
I've learned a lot about my reloading practices since picking up a concentricity gauge a couple months back. What I've learned is that the die itself isn't the source of the problem. Its the expander ball. That thing really wrecks havoc on case neck concentricity which in turn inhibits a well aligned bullet during the seating operation.
After much reading, I decided to test a new process on one caliber to see if I could dial it in. I removed the expander ball in the die and picked up a Sincliar mandrel die body and a carbide expander mandrel from PMA tools for neck sizing. I've run a bunch of tests by FL resizing the case with expander ball removed then running the case through the expander mandrel. My runout is now consistently less then .002 inches. The expander mandrel from PMA also gives me consistent .002 inch neck tension.
Very happy with the results and am planning on expanding this process to all calibers I reload.
After much reading, I decided to test a new process on one caliber to see if I could dial it in. I removed the expander ball in the die and picked up a Sincliar mandrel die body and a carbide expander mandrel from PMA tools for neck sizing. I've run a bunch of tests by FL resizing the case with expander ball removed then running the case through the expander mandrel. My runout is now consistently less then .002 inches. The expander mandrel from PMA also gives me consistent .002 inch neck tension.
Very happy with the results and am planning on expanding this process to all calibers I reload.
I do pretty much same as copperking with Sinclair mandrel die with Sinclair turning mandrel that gives me .002 neck tension. I use Redding neck bushing die with expander ball removed. I'm gonna order Harrell's dies with my upcoming build to compare and to bump shoulders more often as it seems to work better for accuracy for me.
Yep, that's them.
There's two types of mandrels, a "Turning" mandrel and an "Expander" mandrel and Sinclair and PMA both make similar mandrels for both. I first tried Sincliar's carbide "Turning" mandrel. They advertise that it will give you .002 inches of neck tension. I found it to be closer to .004. I then looked at their Expander mandrel, as they size a little larger, but Sinclair only offers that one in stainless steel. I prefer the carbide because you don't need to use lube...but Sinclair for whatever reason, doesn't have an Expander mandrel in carbide.
PMA does and it's spec'd out almost identically to the Sinclair. I got the Expander mandrel from PMA and have been getting excellent results.
I haven't tried stainless steel. They are significantly cheaper but from what I've read, you'd need to use case lube. With carbide you don't and from my experience, it operates smooth as butter. That to me makes it worth the extra cash.
One other point. Sinclair makes a nice concentricity gauge.
http://www.sinclairintl.com/reloadi...s/sinclair-concentricity-gauge-prod37479.aspx
But if you're willing to spend some more cash, go with the 21st Century. That's what I bought and am nothing but pleased with it. The turning wheel is a really nice feature. I really enjoy tinkering with mine...very cool gadget!
http://www.xxicsi.com/concentricity-gauge.html
http://www.sinclairintl.com/reloadi...s/sinclair-concentricity-gauge-prod37479.aspx
But if you're willing to spend some more cash, go with the 21st Century. That's what I bought and am nothing but pleased with it. The turning wheel is a really nice feature. I really enjoy tinkering with mine...very cool gadget!
http://www.xxicsi.com/concentricity-gauge.html
I'am pleased with the Accuracy One concentricity gauge. Sold the first two I bought.
Ben
Ben
I've ran bushing dies with no expander ball for years, and became concerned about runout, bought the 21st Century gauge with the wheel and love it. Runout can come from many places, I found just switching from Redding sizing dies to Whidden dies cut my runout in half, so much so I rarely measure it anymore.
The worst I had was .003", most was in the .0015" range, now under .001" in most, I've only read and can't say when concentricity affects your target.
Looking back, the worst runout I ever had was in 7 saum using a RCBS x-die, not using the mandrel part for effect. A quality die goes a long ways.
The worst I had was .003", most was in the .0015" range, now under .001" in most, I've only read and can't say when concentricity affects your target.
Looking back, the worst runout I ever had was in 7 saum using a RCBS x-die, not using the mandrel part for effect. A quality die goes a long ways.
I think you may have got an off mandrel or something. My Sinclair T26 mandrel is as advertised: .261 and E26 is .262. Lapua 123 Scenar is .263 to .2635 for .002-.0025 neck tension with the turning mandrel. Mine are SS though, not carbide.
jepp2
Gold $$ Contributor
I have the Sinclair and the Hornady concentricity gauges. I never use the Hornady, and I like the Sinclair, but if I was buying today I would buy the 21'st Century gauge.
Are you annealing your brass? That sounds like a lot of springback. My carbide mandrel is exactly 0.002 under caliber.
One caveat on the gauge itself. Think long and hard if choosing a gauge that uses a pin (like Hornady and a few others) that will cause pressure against the seated bullet. The gauge that has the "flippy" type pin exerts next to nothing as far as pressure goes. I don't know what each is called, but you will know it when you see it.
I'll agree with that - the first one I made, around 10 years ago used a plunger type dial gauge, it worked ok but recently I decided I wanted something a little more sensitive.
My new one has a lever dial indicator and it's like chalk and cheese.
Plunger gauge:
Lever gauge.
an a short video of the lever gauge in action: HERE
One thing that someone should mention, is that there is a difference between a concentricity gauge and a runout gage.
Sinclair's, like those 1066's photo are runout gauges(even though Sinclair merchandises as concentricity). Runout gauges show every disparity, and you will not have straight ammo until total indicated runout is verified low.
Concentricity gauges, what I refer to as neck benders, are those that pin seated bullets while measuring nearest that pinned end. Hornady provides an example of this. These are merely a gimmick, and won't help you reach truly straight ammo.
The root cause of runout is sizing of thickness variance. So even with perfect dies and methods, there is no guarantee in eliminating runout. But you can mitigate much of it with minimal sizing of select cases, having very little thickness variance.
Pulling an expander button can cause runout issues, and like mentioned, mandrels actually reduce runout.
Sinclair's, like those 1066's photo are runout gauges(even though Sinclair merchandises as concentricity). Runout gauges show every disparity, and you will not have straight ammo until total indicated runout is verified low.
Concentricity gauges, what I refer to as neck benders, are those that pin seated bullets while measuring nearest that pinned end. Hornady provides an example of this. These are merely a gimmick, and won't help you reach truly straight ammo.
The root cause of runout is sizing of thickness variance. So even with perfect dies and methods, there is no guarantee in eliminating runout. But you can mitigate much of it with minimal sizing of select cases, having very little thickness variance.
Pulling an expander button can cause runout issues, and like mentioned, mandrels actually reduce runout.
No, I'm not. And that may explain it...which isn't lost on me.
I don't anneal nor do I use bushing dies. Just standard Redding dies. I might do both if I were shooting competition but for my purposes, which is mostly varmint and bench shooting against myself, I just don't want the hassle that comes with bushing dies and annealing.
Using the process I outlined above, I get acceptable results compared to what I was getting (.007+ runout). Brass life my be reduced but seems like I lose most cases to pocket primer reduction and not neck degradation. All the extra work with bushing dies and annealing just doesn't seem to produce a worthwhile ROI...or at least for what I'm doing.
Very true! I thought I had this reloading thing figured out until I bought my 21st Century Concentricity gauge.
Sleepless nights followed....
Yeah, they make a really nice one. Costly, but it's a heck of a device.
Shynloco
You can lead a horse to water, but ........
There's your best answer for best results...the 21 Century Concentricity Gauge. I've owned or own both the Sinclair and the Hornady models. I sold the Sinclair after buying the 21st Century gauge (much better and more accurate gauge) and use the Hornady as a door stop as in all good conscious, cannot bring myself to sell that POS Hornady (so called "gauge") to anyone as I'd be victimizing them with a worthless piece of crap that is incapable of providing accurate and meaningful results. Sorry for the soapbox rant.
Alex
ridgeway
Silver $$ Contributor
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