Concentricity Gauge - Measuring Run Out

[PharmShooter]

Quick question:

After you started to load a group of rounds do you use a concentricity gauge to see how you're doing? Also, where is the best place along the bullet and/or brass to measure?

What are your expectations regarding how much is too much run out?

Thanks,

Brad

 

[ChrisGarrett]

Quick question:

After you started to load a group of rounds do you use a concentricity gauge to see how you're doing? Also, where is the best place along the bullet and/or brass to measure?

What are your expectations regarding how much is too much run out?

Thanks,

Brad

You'd load up a few and measure along the bullet's ogive and see what you see.

You can also, with the getter gages, measure at the neck before reloading and somewhere along the case body, again, before you load up your rounds. This lets you differentiate between runout caused from firing brass and from the reloading process.

.000"-.002" is ideal, .002"-.004" and ehhh, over .004" and you may notice things on paper.

9mm vs. 45, Glock vs. 1911, on top vs. on the bottom...you get the picture.

Chris

 

[JGorski]

This is where I place the dial, I like no more than .003", then I adjust the runout, a nice thing about the Hornady gauge.

 

[MajorHeadTrauma]

I use the same gauge but I measure closer to the ogive. With good dies, my run out is way less than .001".

 

[M40_A1]

One tip on using that Hornady gauge-
I apply pressure against the spring-loaded spindle with my right thumb (near the bullet's tip) as I rotate the cartridge. There's a bit of play between the spindle and the frame (push against the spindle and watch the needle move), and if you don't push it to one side your readings will be erratic. I find just pushing back toward the gauge easy and quick.

 

[JGorski]

One tip on using that Hornady gauge-
I apply pressure against the spring-loaded spindle with my right thumb (near the bullet's tip) as I rotate the cartridge. There's a bit of play between the spindle and the frame (push against the spindle and watch the needle move), and if you don't push it to one side your readings will be erratic. I find just pushing back toward the gauge easy and quick.

I get the same readings when I just tried that, so I feel there's no need to push anything.

 

[Former0302]

One tip on using that Hornady gauge-
I apply pressure against the spring-loaded spindle with my right thumb (near the bullet's tip) as I rotate the cartridge. There's a bit of play between the spindle and the frame (push against the spindle and watch the needle move), and if you don't push it to one side your readings will be erratic. I find just pushing back toward the gauge easy and quick.

Hey that's a good tip, I'll have to try that out....I've stopped using mine out of frustration.

The other thing I've found with this tool is that correcting the concentricity can be frustrating too, too much torque on the screw to correct and you can over-correct, too little and it doesn't change anything. If you go back and forth too many times trying to get it down to .002 or below you then start changing the neck tension...which could affect accuracy just as much if not more than concentricity.

Those that use this tool, any tips other than developing a feel for it over time?

 

[Beepy]

I have not found the need to put pressure with my Hornady Gauge, does yours have the right spring tension. I am a super type A person so I want less than 0.001" I can usually do that if I use a Redding bushing sizer and a Redding Comp Seater. I'm really OK with up to 0.002-0.003 but you know how we all have to be perfect! Check FGMM for runout... I get up to 0.004-0.006"

 

[Beepy]

Oh, and I I can't fix the runout within 2 tries, I leave it alone... you do get a feel for how much you need to torque that little plastic screw down for 1-2 thousandths. I wonder how long that little plastic thing is supposed to last anyway.

 

[PharmShooter]

Thanks for the comments...very helpful!

 

[RTK]

Quick question:

After you started to load a group of rounds do you use a concentricity gauge to see how you're doing? Also, where is the best place along the bullet and/or brass to measure?

What are your expectations regarding how much is too much run out?

Thanks,

Brad

You are in for it now. Once you buy one of those things you are going to go insane toying for perfection..............

 

[demolitionman]

If my runout is less than .004 I'm fine with that. .005, doesn't bother me much either. I shoot for .003 or less. Typically I can keep the loads at or under .003 measured just ahead of the case neck. I'm sure my numbers would increase if I did it closer to the ogive. If I have the right load, my groups shoot sub moa no problem. I'm not using a competition seater die just yet. I do want to get one to stabilize the case more during bullet seating process. With a standard die I do 3 seperate turns as I ease the press down. Seems to work fairly well.

 

[M40_A1]

I have not found the need to put pressure with my Hornady Gauge, does yours have the right spring tension.

It would have nothing to do with spring tension. It has to do with machining tolerances and lateral (sideways) play. The hole in which the plunger spindle sits has to be large enough for the spindle to move through it. That means the hole in the frame has to be some dimension larger than the spindle. I'm not pushing in on the end of the spindle's black knob. I push on the silver part of the spindle that contacts the nose of the bullet. I push it from me (the front) toward the gauge (the rear) and get about .0015" needle movement. Maybe that is O.K. in some books, but I want to see true readings as I rotate the cartridge, and by pushing the spindle to a solid stop (the side of the hole in the frame) I know the readings are repeatable and consistent.

 

[insight3b]

I don't care about measuring run-out or checking concentricity...total waste of time

 

[JGorski]

When I reloaded some 6 Creed yesterday I noticed when correcting runout with the Hornady tool, if you have lets say .005" runout, just turn the screw in till the dial goes to .012",(of course you're starting back at 0) that seemed to work very well for me, gets it within .003" or less most times. In other words, you go .002" past twice as much runout as you're getting.

 

[X-fan]

I don't care about measuring run-out or checking concentricity...total waste of time

I have come to the same thinking.
If its a larger bullet/case I don't care as long as I am withing 6 thou. Most of the time I am much less.

I have run into die/brass problems before so it isn't the worse thing in the world to spot check your finished product.