RCBS Concentricity Gauge

[CWLONGSHOT]

Does anyone have one? Use it allot?

I have this RCBS. Would like the Sinclair. Simply because of the blocks. RCBS uses aluminum V blocks and Sinclair uses ball bearings.

Its difficult at best to hold true to spin. It is a bit deceiving because the gauge in .25 per line where many are .5 per line. So what seems like allot of runout when that guage jumps 3-4 or even 5 lines is really .001 ish.

My V blocks are getting worn.



Its like gualing and the cases are difficult to turn smoothly. I have a email into RCBS sending pics hoping they will either send or sell me new blocks. Id buy a Sinclair but havent found one.

How do you like it do ya have any advice or tricks?

CW

Just posted a video on Seater dies and included some of this guage as I wanted to show runout. Its near end of the video.

Universal & Match Seater dies

Frankfort Arsenal UNIVERSAL seater die. Some resemblance to a MATCH seater die & produces a good result but not the same.

rumble.com

 

[462]

Many times over many years I've thought of buy one. Never have, though, because finding runout is one thing, but correcting it probably requires more equipment and more fiddling than I want to get involved with.

 

[Ian]

Throw that piece of crap in the trash and buy a Sinclair or Hornaday gauge.

 

[462]

Throw that piece of crap in the trash and buy a Sinclair or Hornaday gauge.

Ian,
Hornady question: By applying pressure one part of the cartridge neck, to correct its runout, won't it screw up existing neck tension?

 

[CWLONGSHOT]

Throw that piece of crap in the trash and buy a Sinclair or Hornaday gauge.

Hahaha.

Its fine... But for those blocks!

I been looking & watching videos and they aren't, really, all that different. I wish I could just buy the Sinclair but I haven't found one. Besides 150$ ish invested here already.
Tomorrow Ill call RCBS and see what can be done.

If I had known, I wouldn't have bought the RCBS.

CW

 

[CWLONGSHOT]

Ian,
Hornady question: By applying pressure one part of the cartridge neck, to correct its runout, won't it screw up existing neck tension?

Exactly the problem they DO EFFECT nect tension and Id wager that the NECK tension is far more important than that couple thousandths discrepancy.

 

[waco]

The only one I’ve owned is the Sinclair. Happy with it.

 

[Ian]

Ian,
Hornady question: By applying pressure one part of the cartridge neck, to correct its runout, won't it screw up existing neck tension?

I don't know. It seemed like a dumb idea to me, too, so I never tried it.

 

[462]

Okay, here's another question: Using Sinclair's gauge, for instance, to determine runout, would Lee's collet neck sizer die correct it? With the decapping pin removed, of course.

 

[Ian]

Depends. The main use of a concentricity gauge is to determine exactly what part of the process (including the FIRING process!!) is causing concentricity issues. If it's the sizing process such as off-center flash holes and a Lee collet sizing die, then pull out or grind off the decapping pin and try again to see if it's the press alignment causing the problem. If you meant post-sizing a loaded cartridge with the collet die....um, no.

 

[fiver]

the RCBS just measures the issues.
i use one to sort out the crooked junk.
it's amazing how bad once fired cases can be, and how a good rifle can straighten them out.
i also use it to measure other stuff.

it isn't the easiest tool to use and it takes a lot of practice holding the case down in those VEE blocks so you don't get .0030 run out on everything.
i really wish they had some sort of spring pressured tab a guy could use to hold the case in place.

 

[CWLONGSHOT]

Thats what I always think too. Something to hold the case more consistently.

Yes these tools only show the problem. Not where they come from and dont fix them.

Had not thought about a OOL flash hole causing issues.... havent really seem many noticeably "out". But can now see the possible issue.

I have always like the results of THAT Lee Collett die.

That and the Forester Match sizer is what Midway fudged up in my last order and now that Forester die is out of stock.

 

[462]

If you meant post-sizing a loaded cartridge with the collet die....um, no.

Yep, meant post-sizing.

 

[dannyd]

call RCBS and get a new set of v blocks under warrant. I think the dial indicator has a 1 year warranty but rest is under lifetime. The first Sinclair did not have rollers; I have that one and the RCBS.

 

[Ian]

A person could drill pockets in the vee blocks for ball bearings and epoxy them in about 3/4 of the way to give smooth bearing surfaces. Not rollers, but at least a smooth, single point of contact. Or just buy a better tool.

 

[CWLONGSHOT]

A person could drill pockets in the vee blocks for ball bearings and epoxy them in about 3/4 of the way to give smooth bearing surfaces. Not rollers, but at least a smooth, single point of contact. Or just buy a better tool.

Thats a idea!
Maybe, I see what I can jig up if, I get new blocks sent tomorrow.

CW

 

[dannyd]

I like the RCBS unit.

 

[CWLONGSHOT]

Looking closer this AM after a talk last night with a long time machinest... The gauge was dirty. I cleaned as he suggested abd reset all and took some reading with shim stock I had.

I did this before and after and its remarkable what a lil dust abd light "gunk" do!!

Here is before:



Here is after.



I missed a call with RCBS as my Dr called confirming a visit. Grrr

So waiting on second call now.

CW

 

[Ian]

What, exactly, did you clean?

 

[CWLONGSHOT]

Basically dust from shaft top and bottom air and a tooth brush.
Didnt see allot but did see some accumulation. I assumed a light oil of some kind attracted it??
In any event it cause some kinda "drag" cause it obviously measures more accurately. I didn't think I did allot but solid proof something occurred.