21 century vs Sinclair’s digital concentricity gauge

[DngBat7]

I know everyone is gonna say 21 century, but I’m drawn to Sinclair’s digital concentricity gauge. Easy and quick to read. Easy to set at the low point in the brass. Opinions and reviews welcome


Thanks

 

[jackson1]

Not a fan of digital dial indicators, prefer the swinging hand. The old school indicators are just more intuitive to me. Spent my life as a tool maker and used them daily. Digital dial indicators involve to much thinking.

 

[Elwood]

Go for the 21st Century.

I have the Sinclair gauge and While I believe it works for the intended purpose of checking concentricity I have modified mine to check base to Ogive measurements.
The problem is the gauge appears to jump, I was measuring some Bergers recently and had three different groups separated by 1 thou, .46. .47 and .48 when all of a sudden I had a .51 followed by another and then a .50. I then checked the bullets measured at .47 and they now measured.50. A bit fiddling about and setting the dial back to zero I then managed to get it to measure the .47 bullets back at .47.
I have since been on the Sinclair website and looked at their bullet sorting tool which would appear to use the same digital dial indicator as their concentricity gauge , and while reading the reviews for the bullet sorting tool someone else had exactly the same problem as I encountered.
This isn't a bash at Sinclair, I have used many of their products over the years without problem, but when you're measuring something as precise as runout or bullet measurements then I believe quality measuring equipment is a absolute must.

 

[jackson1]

Just a few more thoughts on these gauges. I own and use the Sinclair tool. I in my humble opinion the 21st Century tool is better engineered. First a 0 to 1" indicator is the wrong tool for the job. A test indicator with plus/minus 0.030" of travel is the proper tool for the job. Second, the wheel used to spin the cartridge is a better way than fingers. Had my Sinclair before the 21st century came out, so I will live with it, but if I had to do it over again, the 21st Century tool would be my choice. Now in my retirement, I have a number of indicators at home and have rigged my gauge to use a test indicator.

 

[JBO]

21st

 

[SteveOak]

Go for the 21st Century.

I have the Sinclair gauge and While I believe it works for the intended purpose of checking concentricity I have modified mine to check base to Ogive measurements.
The problem is the gauge appears to jump, I was measuring some Bergers recently and had three different groups separated by 1 thou, .46. .47 and .48 when all of a sudden I had a .51 followed by another and then a .50. I then checked the bullets measured at .47 and they now measured.50. A bit fiddling about and setting the dial back to zero I then managed to get it to measure the .47 bullets back at .47.
I have since been on the Sinclair website and looked at their bullet sorting tool which would appear to use the same digital dial indicator as their concentricity gauge , and while reading the reviews for the bullet sorting tool someone else had exactly the same problem as I encountered.
This isn't a bash at Sinclair, I have used many of their products over the years without problem, but when you're measuring something as precise as runout or bullet measurements then I believe quality measuring equipment is a absolute must.

Could you please post pix of the mod you did and how you measure base to ogive?

I agree that the plunger type indicator is not the best tool for measuring concentricity. I have an idea to adapt the Sinclair to use a test indicator. I just need to get around to buying the clamp.

 

[Elwood]

Could you please post pix of the mod you did and how you measure base to ogive?

I agree that the plunger type indicator is not the best tool for measuring concentricity. I have an idea to adapt the Sinclair to use a test indicator. I just need to get around to buying the clamp.

As simple as drilling a hole in the base to accept a Hornady comparator (tightly) the bullet ideally needs to sit in a sleeve to eliminate sideways movement as much as possible and the bottom of the dial needs to have a flat base the same as the Sinclair bullet sorting tool.

I'm currently in the process of making my own bullet sorting dial using individual parts, but as this conversation is about concentricity gauges that's as much as I will say.

 

[1066]

Here's a couple of my handmade ones:

 

[SteveOak]

Thanks Elwood

 

[jepp2]

I used the Sinclair dial gage unit for a while, now I use the 21'st Century all the time and the Sinclair is collecting dust (along with the Hornady unit).

 

[Grimstod]

This one reads concentrically and allows you to fix it. Obviously its track record proves it works.