Concentricity??

[Jack300WSM]

.001"-.004" runout on this Hornady concentricity tool. Haven't had it long and was wondering about this runout range. Good, bad?? Not really sure if I should put more bs into this skull of mine as I got enough going on as it is . Stuff I'm using on this setup is Redding full length standard die, Sinclair expander mandrel and Forster Ultra seater, 300wsm Nosler brass and 165g Sierra Gamechanger. Pretty consistent as is around 1/2-3/4" groups when I do my part but always trying to learn something new

 

[Reelamin]

Hey bud....I'll just say.... obviously you have not spent enough money on your equipment dont you know this?? LOL...having a kinda grumpy day and getting a chuckle from you might help.

 

[Jack300WSM]

I guess I watch too many Eric Cortina YouTube videos…

 

[Reelamin]

I guess I watch too many Eric Cortina YouTube videos…

Oh no....my opinion flat out is you have spent enough and factually I have never even checked concentricity on any round I have loaded for 45 years. I like Eric a lot especially when he points out how he just spent a ton of money and time and it was absolutely a waste of money and time. LOL.....my first post was just hoping I could prompt a chuckle from you as my perception and humor comment attempt really really comes up a lot.

 

[Seabeeken]

Had issues with my 250ai. Couldnt get better than .7" so i checked runout. .010 runout. Die was inducing it. Sent it back and they repaired it. Got runout to .002 but didnt tighten group much at all. New brass and shoots .5 easily. Havent touched my runout tool since. My rifles shoot .2-.5" without any concern about runout

 

[Jack300WSM]

All good. I just got this tool after nearly 30yrs of "not" needing one. Don't know if it makes any difference or not. I'd probably never notice a difference and I'm guessing those numbers are typical. Always wondered if standard dies were just as good as those match/benchrest dies though

 

[DJ Fergus]

I don't check runout very often. As in just about never. I did a couple of times and had about as much runout as you show. Still got under 1/2 moa & better without any trouble. Im not telling you not to check. Im just saying that I won't unless I'm having to troubleshoot.

 

[nksmfamjp]

Well, those numbers sound small. I have no idea what 0.001-0.004" on that gage means.

IOW, does your rifle chamber hold the tip and base?

I ask because on my rifle, the bolt face pushes the case body taper and case shoulder taper into mating tapers in the chamber. My case base diameter really doesn't change from fired to sized more than a few 0.0001's. So, I consider the base as a datum and the body/shoulder surface as formed by the die as a datum. When spun, this shows me the cartridge centerline as it fits in the chamber. Then, I want to know if the tip of my bullet, well actually about 0.1" back from the tip is pointed. Is it aligned with the case axis, or a couple 0.001's misaligned? That is what drove my purchase.

That said, the Hornady tool may work very well. I just cannot determine from its design, if it will be helpful. I returned mine.

I also tried straightening ammo. That was a cluster! I think some made a right turn exiting the muzzle! I made a 0.5"-0.75" AR shoot 1.5" groups!

Good luck with your new tool. Hope it gets you where you want to go.

 

[QuietTexan]

Where are you measuring it at?

Two things - one if you're on the neck and don't turn, then you're going to pick up an outside thickness variance that your mandrel is pushing outwards. Two is a dial isn't the best tool for measuring runout, and the spring in the plunger could be pushing the dial out of line with the surface being measured rather than actually indicating a change in the surface. A test indicator is the proper tool to measure run out with. I use a dial for run out all the time... but on a brake rotor the tolerance is a lot larger than a brass case. Higher end concentricity gauges use test indicators for a reason. A high quality dial will beat a low quality test indicator easily, but not a high quality test indicator.

Meaning ultimately I don't think the .001-.004" you're measuring is bad, and wouldn't worry about it for a second. If you were seeing 0.010" or more I'd bet you could see that on the target, but you're fine where you're at. I had a Hornady tool once and sent it back, it ultimately was just frustrating because it didn't show anything meaningful enough to cause me to change anything I was doing at the time.

https://bullettipping.com/products/concentricity-gauge/http://www.xxicsi.com/concentricity-gauge.html

 

[Jack300WSM]

Measuring a loaded round with tool on bullet ogive is what I was doing. I turn necks but hadn't thought about checking them

 

[asd9055]

I guess I watch too many Eric Cortina YouTube videos…

What I am learning is some videos are more about selling new gadgets than anything else

 

[Jack300WSM]

What I am learning is some videos are more about selling new gadgets than anything else

I did buy one of his tuner brakes for one of my problem setups and it made a huge difference in comparison to what I was getting with burning through components trying to figure out what she liked.

 

[asd9055]

I did buy one of his tuner brakes for one of my problem setups and it made a huge difference in comparison to what I was getting with burning through components trying to figure out what she liked.

I believe in tuners, I have had them for 25 years.

 

[baldhunter]

.001"-.004" runout isn't bad.What I've noticed the more times you load your brass and the harder it gets,the more runout your probably going to see.Could be from resizing or even seating the bullet in hard brass.When I see .080 - .010,I separate those from the rest of the group.Those are good for burners when rough sighting in scopes.They still group OK,but can be out of the group a little.Just keep those in a different group of fired brass so you don't have to look for them again.For hunting rounds,I like once-fired brass.