Sinclair Concentricity Gage Questions

flashhole · October 19, 2009, 07:51 PM

For those of you who own a Sinclair Concentricity Gage - did you buy it with the Sinclair dial indicator or did you purchase a different indicator?

Is the dial indicator that comes with the tool adequate or should it have finer resolution?

If you purchased a different make indicator what kind did you get and do you like it?

What about a digital indicator? Does it have a distinct advantage over the dial type?

How important/useful is the extender finger on the dial indicator?

Lots of questions but I only want to do this once and I'm sure a few members will express an opinion.

Thanks.

**Unclenick** · October 19, 2009, 08:53 PM

Flash,

I don't have that one, but I own a lot of both digital and analog (dial or meter) measuring equipment. In the example of the dial indicator for a runout gauge, I feel the mechanical dial has a serious advantage. I would not want one with ten-thousandths for that application, as the touchdown is too touchy and will slow you down getting it right. But if you have one with half thousandth graduations or even a large dial with one thousandth graduations, you can easily see the dial move within each graduation, revealing much finer movement. I have an old Interapid indicator with a small dial with half-thousandth graduations that I use on my lathe for setups all the time, and doing sub-quarter-thousandth runout setups on it is easy. I only drag out the Fowler ten-thousandths dial when I really need to. Your digitial indicator with half thousandths will just round up or down from or to the nearest half thousandth. When digits flash rapidly you have to ignore them in favor of one of the less significant digits because blurring numbers don't make it easy to tell whether they are going up or down? The dial needle, on the other hand, makes it immediately obvious which way it is headed and which way you need to push a bullet to straighten a cartridge.

Extensions and tips for linear plunger gauges are useful at their face value. The elephants foot, for example, is great for bullet tips and round shapes under a plunger type indicator. Swing arm indicators, like the center finding gauge I own, sometimes need a long probe to reach into a critical position. But the longer the arm, the shorter the lever, so if you double its length, the indicator's resolution is cut in half. Then the half-thousandth graduations become one-thousandth graduations, so keep aware of that when using one.

I know the gauges like the Sinclair that support the case at two points for rotation are popular, but for loaded cartridge runout you have to put the indicator on the tip of the bullet to see as much dial movement as you do from putting the indicator on a bullet next to the case mouth in a gauge that supports the bullet tip at one point and the head on the other end. I find the latter a little easier to get a maximum reading on because the indicator purchase is larger. On the other hand, that style won't reveal runout of an off-axis neck the way the Sinclair style will. The only gauge I am aware of that lets you make both kinds of reading and one the others don't, wall runout back inside near the case head, is the NECO gauge. An invention of the late Roger Johnston, who used to write some for Precision Shooting, it does more different readings than any other such tool I am aware of. It is not cheap, but if you call NECO you can probably get a set of instructions to read to see what you think? I find mine indispensable for sorting new cases.

flashhole · October 20, 2009, 04:31 PM

Nick - I think you said at one time you have the NECO product. Does the V-block case nesting method facilitate easy/accurate cartridge rotation? The Sinclair bearing assembly looks pretty easy to use.

Also, the NECO system has the dial sensor that lays on the side of the case as opposed to a straight shaft that pokes the case. Is there an advantage to one over the other?

Do you have the case correction/forming fixture as well, does it work as advertised?

**Unclenick** · October 20, 2009, 05:34 PM

Yes, I have the NECO. I also have a Forster that I got at a gun show in the 80's that uses a plunger indicator (often called a vertical indicator verses a horizontal indicator with a swing arm tip). In both instances the indicator's position has to be set, at least for the first round. The horizontal indicator has less total distance it can measure, so it winds up being moved more often. The plus is that the once the indicator is in position, it stays put. The plunger type has a longer range of measurement (one inch for mine) that lets you lift the plunger probe a good distance from the object under test, so you don't have to move it as often. However, the standard tip is a small ball bearing that can slide off cylinders. I find it slightly harder to set perpendicular to the case for that reason. The spring-loaded plunger wants to slide off one way or the other. But once you get it set, you are fine. You can also get a tip for it called elephant's foot, which is a flat disc tip that will ride small cylindrical shapes a little more easily.

The cases seem to turn in the V's just fine. Since the Forster also uses V's, I haven't tried a ball-bearing type to compare? Indeed, I usually leave the Forster set up for finished cartridge runout tests, and leave the NECO set up with the extended anvil to sort for wall runout, in which instance the V is not used. In a photo the ball looks like it would be smoother, but that assumes it rotates in its holder easily. I don't know how that is managed on those holders. If it is just sitting in a cup, the ball may turn no more easily against the cup than a case does against a V? So it may be more a way to avoid the cost of machining a V than to improve rolling?

steve4102 · October 20, 2009, 06:24 PM

I have the Sinclair gauge with the Sinclair dial indicator, works like a charm, I see no need to go digital unless you just feel the need.

flashhole · October 21, 2009, 05:18 AM

Nick - do you have the NECO gage only? $168

Or do you also have the Cartridge Alignment Tool (CAT)? Does this thing work as advertised? $207 w/gage above

October 19, 2009, 07:51 PM	#1
flashhole Senior Member Join Date: February 9, 2005 Location: Owego, NY Posts: 2,000	Sinclair Concentricity Gage Questions For those of you who own a Sinclair Concentricity Gage - did you buy it with the Sinclair dial indicator or did you purchase a different indicator? Is the dial indicator that comes with the tool adequate or should it have finer resolution? If you purchased a different make indicator what kind did you get and do you like it? What about a digital indicator? Does it have a distinct advantage over the dial type? How important/useful is the extender finger on the dial indicator? Lots of questions but I only want to do this once and I'm sure a few members will express an opinion. Thanks. __________________ ,,, stupidity comes to some people very easily. 8/22/2017 my wife in a discussion about Liberals. Are you ready for civil war?

October 19, 2009, 08:53 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Flash, I don't have that one, but I own a lot of both digital and analog (dial or meter) measuring equipment. In the example of the dial indicator for a runout gauge, I feel the mechanical dial has a serious advantage. I would not want one with ten-thousandths for that application, as the touchdown is too touchy and will slow you down getting it right. But if you have one with half thousandth graduations or even a large dial with one thousandth graduations, you can easily see the dial move within each graduation, revealing much finer movement. I have an old Interapid indicator with a small dial with half-thousandth graduations that I use on my lathe for setups all the time, and doing sub-quarter-thousandth runout setups on it is easy. I only drag out the Fowler ten-thousandths dial when I really need to. Your digitial indicator with half thousandths will just round up or down from or to the nearest half thousandth. When digits flash rapidly you have to ignore them in favor of one of the less significant digits because blurring numbers don't make it easy to tell whether they are going up or down? The dial needle, on the other hand, makes it immediately obvious which way it is headed and which way you need to push a bullet to straighten a cartridge. Extensions and tips for linear plunger gauges are useful at their face value. The elephants foot, for example, is great for bullet tips and round shapes under a plunger type indicator. Swing arm indicators, like the center finding gauge I own, sometimes need a long probe to reach into a critical position. But the longer the arm, the shorter the lever, so if you double its length, the indicator's resolution is cut in half. Then the half-thousandth graduations become one-thousandth graduations, so keep aware of that when using one. I know the gauges like the Sinclair that support the case at two points for rotation are popular, but for loaded cartridge runout you have to put the indicator on the tip of the bullet to see as much dial movement as you do from putting the indicator on a bullet next to the case mouth in a gauge that supports the bullet tip at one point and the head on the other end. I find the latter a little easier to get a maximum reading on because the indicator purchase is larger. On the other hand, that style won't reveal runout of an off-axis neck the way the Sinclair style will. The only gauge I am aware of that lets you make both kinds of reading and one the others don't, wall runout back inside near the case head, is the NECO gauge. An invention of the late Roger Johnston, who used to write some for Precision Shooting, it does more different readings than any other such tool I am aware of. It is not cheap, but if you call NECO you can probably get a set of instructions to read to see what you think? I find mine indispensable for sorting new cases. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

October 20, 2009, 04:31 PM	#3
flashhole Senior Member Join Date: February 9, 2005 Location: Owego, NY Posts: 2,000	Nick - I think you said at one time you have the NECO product. Does the V-block case nesting method facilitate easy/accurate cartridge rotation? The Sinclair bearing assembly looks pretty easy to use. Also, the NECO system has the dial sensor that lays on the side of the case as opposed to a straight shaft that pokes the case. Is there an advantage to one over the other? Do you have the case correction/forming fixture as well, does it work as advertised? __________________ ,,, stupidity comes to some people very easily. 8/22/2017 my wife in a discussion about Liberals. Are you ready for civil war?

October 20, 2009, 05:34 PM	#4
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Yes, I have the NECO. I also have a Forster that I got at a gun show in the 80's that uses a plunger indicator (often called a vertical indicator verses a horizontal indicator with a swing arm tip). In both instances the indicator's position has to be set, at least for the first round. The horizontal indicator has less total distance it can measure, so it winds up being moved more often. The plus is that the once the indicator is in position, it stays put. The plunger type has a longer range of measurement (one inch for mine) that lets you lift the plunger probe a good distance from the object under test, so you don't have to move it as often. However, the standard tip is a small ball bearing that can slide off cylinders. I find it slightly harder to set perpendicular to the case for that reason. The spring-loaded plunger wants to slide off one way or the other. But once you get it set, you are fine. You can also get a tip for it called elephant's foot, which is a flat disc tip that will ride small cylindrical shapes a little more easily. The cases seem to turn in the V's just fine. Since the Forster also uses V's, I haven't tried a ball-bearing type to compare? Indeed, I usually leave the Forster set up for finished cartridge runout tests, and leave the NECO set up with the extended anvil to sort for wall runout, in which instance the V is not used. In a photo the ball looks like it would be smoother, but that assumes it rotates in its holder easily. I don't know how that is managed on those holders. If it is just sitting in a cup, the ball may turn no more easily against the cup than a case does against a V? So it may be more a way to avoid the cost of machining a V than to improve rolling? __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

October 21, 2009, 05:18 AM	#6
flashhole Senior Member Join Date: February 9, 2005 Location: Owego, NY Posts: 2,000	Nick - do you have the NECO gage only? $168 Or do you also have the Cartridge Alignment Tool (CAT)? Does this thing work as advertised? $207 w/gage above __________________ ,,, stupidity comes to some people very easily. 8/22/2017 my wife in a discussion about Liberals. Are you ready for civil war?

October 20, 2009, 06:24 PM	#5
steve4102 Senior Member Join Date: December 23, 2005 Location: Minnesota Posts: 2,955	I have the Sinclair gauge with the Sinclair dial indicator, works like a charm, I see no need to go digital unless you just feel the need.