Which concentricity gauge(s) do you use?

[Bill2905]

For those who measure runout on cases or loaded rounds, which concentricity gauge(s) do you use and what are your overall thoughts on them?

Thanks

[Robinhood]

I made my own. But I have access to the tools.

[Orezona]

I was gifted a Sinclair back in August. It seems very nice.

[Fuj']

Like Robinhood I've done my own, however with my latest cartridge
and the Lee Collet die, I just put them in the box and head to the
range. :thumb:

[Bill2905]

Like Robinhood I've done my own, however with my latest cartridge
and the Lee Collet die, I just put them in the box and head to the
range. :thumb:

Nice. I'm hoping to get there some day.

[yobuck]

Nice. I'm hoping to get there some day.
You talking about getting to the range or making your own whatchamicalits?

[Steeltrap]

I use the Sinclair concentricity gauge. I looked at the Hornady gauge where you have the option of straightening out the bullet, but my only concern (and not founded in any type of science) was if I straightened out any given cartridge, it would then have a different neck tension than the others. The small amount of neck tension difference may or may not have an effect on velocity differences between shots.

[Bill2905]

You talking about getting to the range or making your own whatchamicalits?

Well, I would like to get to the range more often. But, I was referring to improving my loading process to a point where I can just load it and shoot it with confidence.

[Bill2905]

I use the Sinclair concentricity gauge. I looked at the Hornady gauge where you have the option of straightening out the bullet, but my only concern (and not founded in any type of science) was if I straightened out any given cartridge, it would then have a different neck tension than the others. The small amount of neck tension difference may or may not have an effect on velocity differences between shots.

Straightening rounds doesn't seem like something I would be interested in doing. I would prefer to figure out why they don't conform and correct the cause. How do you like the Sinclair gauge? Do you find it fairly easy to use?

[Steeltrap]

Straightening rounds doesn't seem like something I would be interested in doing. I would prefer to figure out why they don't conform and correct the cause. How do you like the Sinclair gauge? Do you find it fairly easy to use?

The gauge is very easy to use. Making adjustments for the cartridge to fit is as easy as falling off a log. The unit has a handle on each "bearing seat" to move back and forward. I align the cartridge....tighten the rear first, then move the front to the front of the brass just below the shoulder, and can adjust the micrometer to measure neck runout or bullet runout.

[yobuck]

The gauge is very easy to use. Making adjustments for the cartridge to fit is as easy as falling off a log. The unit has a handle on each "bearing seat" to move back and forward. I align the cartridge....tighten the rear first, then move the front to the front of the brass just below the shoulder, and can adjust the micrometer to measure neck runout or bullet runout.
Well assuming the case is uniform to start with, wouldnt a better quality seating die be the better way to go about that?
And how much does any of that mean if the chamber isnt up to par as well?

[Fuj']

And how much does any of that mean if the chamber isnt up to par as well?

How true.....Nothing like perfectly straight and true ammo, but the
chamber was cut with a "Detroit Lean".

[Texas10]

Agreed, and it's not hard to check your chamber for concentricity to the rifling. I do it by drilling and tapping the flash hole on a cartridge that the neck measures just a thou or two off center and seat a bullet slightly into the lands, then screw the cartridge onto a section of cleaning rod and insert it into the chamber and remove.

What I will sometimes find is that as I rotate the cartridge 90 degrees at a time and re-insert, I may find little or no drag in one position, and a lot in another. This tells me that as the off center cartridge aligns favorably with an off center chamber, the two complement each other to eliminate drag on the cartridge.

[Fotheringill]

21st Century here. Easy to use and may be operated with its wheel or your very own thumb.

I had the Hornady and returned it.

As above, if not concentric, the fault lies with how the finished product was produced or the case maintained or altered.

[Steeltrap]

Well assuming the case is uniform to start with, wouldnt a better quality seating die be the better way to go about that?
And how much does any of that mean if the chamber isnt up to par as well?

For long distance I shoot a 6.5x55 cartridge. I have a RCBS competition seating die and it works very well. However, if the case isn't concentric from the start, the seating isn't gonna help. I have a Redding type S neck sizing die as well......but if I F\L size the brass, I use a good old Lee F\L sizer that gives me neck alignment like nothing else.

I can't speak to chamber's as the OP's question wasn't about that.

[Robinhood]

I can't speak to chamber's as the OP's question wasn't about that.

When does that stop us?

[yobuck]

So if we took our ammo and checked it for runout, then marked the head of each case with a sharpie at the high point of the runout, then placed each round in the chamber with the mark at the same location, would it help the accuracy of that ammo?

[Steeltrap]

When does that stop us?

Ha!!! True enough!! :rockon:

[Steeltrap]

So if we took our ammo and checked it for runout, then marked the head of each case with a sharpie at the high point of the runout, then placed each round in the chamber with the mark at the same location, would it help the accuracy of that ammo?

IMHO I'd say no. Runout is runout and if the bullet isn't entering the chambering straight...it's (allegedly) going to give the bullet spin a tiny bit "wobbly" and cause larger groups.

Now, in my experience (and I'm no expert by any measurement) that inconsistent neck tensions. bullet concentricity etc will be noticed at ranges of 400 yards and beyond. MOA or a tad over MOA at distances less than 400 yards will still allow you to hit a 5" target......but after 400 yards things really open up.

FWIW

[GaCop]

I've got the Hornady and the RCBS gauges. Hornady is a little bit easier/faster to use.