How many of you serious reloaders use a concentricity gauge?

[The Courier]

Thanks for your reply. I do have to clarify that this tool isn't a "necessary" item you need for rolling your own. The funny story about this tool, is I saw it at the local gunshop for a few weeks before I bought it. At the time I was doing some hunter class centerfire shoots with my 300wsm and it was like this tool kept calling my name. It didn't help any that the main guy kicking my azz by 1 X was using a .223 rem and kept heckling me and the fact I was using a "magnum" for such competitions. I needed that extra edge in the accuracy department and after reading about how concentric ammo helps reduce flyers and shrink groups, I figured this was the most opportune time to try this gadget out. I noticed a difference on my first batch of hand loads and it sold me from there on out. The guy at the club also saw something had changed too, after I started shooting more 100-9x and perfects. I also noticed that the long range accuracy had improved by using this device. Later that fall, I used this same 300wsm and load on a mule deer buck in the Deschutes canyons.
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Like I said earlier, it's not "necessary", but does help to reduce flyers and produce a more consistently accurate load.

With .224 fmj's that were $86/1k with shipping I've got nickle sized groups at 100yrds, if I could shrink em down to the group you have I could rest easy but I will fully admit that my reloading is borderline OCD so to me anything that gets better goups is necessary.

 

[DizzyJ]

Did a lot of thinking on this today. I came up with three thoughts below:

Same lot numbers and case volume will have more of an impact than a centricity gauge.

When I get to the point of using specific brass for my rifle I'll have a use for a concentricity gauge. Until then it's moot. I have more variance in case volume than out of center.

I also wonder how much of a difference it makes when your ammo is .015" or less from the lands?

The closer you are to the lands (within reason) the less effect it will have. This is why sometimes jamming the bullet into the lands can make a big difference in group size.

Keep in mind though, concentricity can be skewed from the bullet being cocked, or the case not being 100% straight (which can happen over multiple firings due to inconsistencies in the brass itself). This is also one reason why some choose to full length resize every single time as opposed to fire forming to the chamber and neck sizing only.

 

[Member 5605]

The closer you are to the lands (within reason) the less effect it will have. This is why sometimes jamming the bullet into the lands can make a big difference in group size.

Keep in mind though, concentricity can be skewed from the bullet being cocked, or the case not being 100% straight (which can happen over multiple firings due to inconsistencies in the brass itself). This is also one reason why some choose to full length resize every single time as opposed to fire forming to the chamber and neck sizing only.

Good to know about the closeness to the lands. Less jump means less chance for something to go partially sideways.

Correct. I measure my headspace from the datum so my brass is within .005" under chamber. You can also only get so many neck size only shots before you need to do a small FL size. I learned that the hard way.

I ensure that my sized brass is under the 5 Thou of chamber after sizing. My .223 brass is .001" under chamber. It's really remarkable how close and dialed in you can get your brass and reduce runout.

Where the heck was everyone a year and a half ago when I went through this?

 

[DizzyJ]

Good to know about the closeness to the lands. Less jump means less chance for something to go partially sideways.

Correct. I measure my headspace from the datum so my brass is within .005" under chamber. You can also only get so many neck size only shots before you need to do a small FL size. I learned that the hard way.

I ensure that my sized brass is under the 5 Thou of chamber after sizing. My .223 brass is .001" under chamber. It's really remarkable how close and dialed in you can get your brass and reduce runout.

Where the heck was everyone a year and a half ago when I went through this?

I joined quite a while back, but until recently, have been spending my time on other forums. Lol

 

[HotRod61]

I have never measured my case concentricity. I have wondered if I am
overlooking an important detail. I do make sure seating die is properly adjusted.
I am not a benchrest competition shooter but I do position shooting Highpower
rifle competition. If I can hold the 10 ring at 600 yard slow fire prone stage
and if I am "On Call" with my shots. I am thinking my reloads are good? Now
if I get that where did that flyer come from? Or I cannot hold the 10 ring?
Something's wrong? Ammo, rifle or me? My reloads are working
good so I have not invested in the concentricity measuring tools. I weigh
each powder charge for the 600 yard stage. I like to say maybe weighing
each charge is only a psychological advantage?? But maybe I am
overlooking this step? Not sure. Good thread good info.
I appreciate the knowledge I can learn from you guys. Thankyou

I with Ron on this one. No need for it. Ron is a great high power shooter.
My reloads always shoot better than me. Don't think it would help me at all.
HotRod

 

[PBinWA]

At the end of the day some pretty straight forward testing always validates the best choices. I waste more time testing things like bullet jump, powder weights, neck tension, ... but if you do it enough the testing will tell you what works best for a particular gun.

Now try finding a standard load that works best across multiple guns and it gets even more tedious.

Kind of depends on what you want to do - shoot or test. If you have the time to do both then you are where I want to be when I retire.

Some shooters that are way better than me also point out that the quality of the gun and the barrel matter a lot more than the ammo. I tend to agree - my "good" guns tend to be way more forgiving.

 

[tarster]

So my dad and I are getting into this, With @Dyjital help he showed me the path to an empty bank account haha just kidding buddy, But in all seriousness, Dyjital was the one who showed me how to check my chamber and starting to push my bullets out to with in .015 of the lands, This did help considerably.. I went from shooting roughly inch to inch and half groups to now with some powder work I am down to half in groups most of the time. My dad had some money left over from his retirement and he wanted something to do with me that we both could enjoy.. so.. we went 70/30 on some tools.. Sinclair concentricity gauge, K&M Neck turner, Annealez annealer, Uniquetek floating tool heads for the Dillon 550, and then also a gempro 250.. I really have not had a chance to go and test out the brass we are still in the process of slowly working through the brass and getting everything, sized, mandrel expanded, annealed, trimmed, deburred, neck turned and then get into the powder side of things.. Interesting, I ran some numbers when we received the gempro 250 since its accurate down to .002 grains I tested out 20 rounds that i had previously loaded on the Hornady powder thrower.. and found most to be close but I did have a variance of almost half a grain most of the time..

 

[ron]

With .224 fmj's that were $86/1k with shipping I've got nickle sized groups at 100yrds, if I could shrink em down to the group you have I could rest easy but I will fully admit that my reloading is borderline OCD so to me anything that gets better goups is necessary.

FMJs?? Good for plinking not a 'tight' group bullet. Try some Sierra Match Kings.
Favorite 100 yard load. 52 SMK---W748+26 grains---W brass. Works in 1/9- 1/8 or
1/7 twist barrels. 748 meters so nice. As always check any loads with
published data.

 

[Otter]

I have a concentricity tool but don't use it much. It is most useful in my opinion to determine if your sizing die and seating die is producing acceptable runout. If the dies are consistently producing runout of less than .003, I don't bother with measuring it any more.

I did a test. I sorted cartridges into .001 or less runout. .001 to .003 runout and .003 up to .006 run out. Shot 5, 5 shot groups at 100 yards and the difference in group size was not enough to justify the practice. In fact the smallest group was the .001 to .003 lot. I did this test twice with a 6mmBR and a 6PPC.

Attached is 5 groups shot at 100 yards with the same BR rifle I did the test with. No sorting occurred for these targets. Dies were checked when I bought them and always produced .003 or less of runout on an estimated 95% or better of all cartridges reloaded.

I would never use a device that attempts to straighten ammo. I would replace the dies instead if there was a problem. Straightening ammo would have to change the neck tension, and on my accurate rifles neck tension has to be consistent for tight groups.

I shoot at Tri County Gun Club, and I've never once seen anyone other than myself use any sort of wind indicator. For most shooters, before you buy a concentricity gauge, I would get 3 or 4 dowels and put some surveyor tape on them to learn what the wind is doing. That will help groups size more than anything for most shooters.

 

[orygun]

As luck would have it, I was recently given a nearly new Hornady Concentricity gauge. Tonight I grabbed one of my reloads and tested it. Came out at .001". So I tested a couple more. Ended up testing 10 and most were .002" or less. Two were .003".
It was nice to verify that part of the process is working out well.

 

[bsa1917hunter]

So my dad and I are getting into this, With @Dyjital help he showed me the path to an empty bank account haha just kidding buddy, But in all seriousness, Dyjital was the one who showed me how to check my chamber and starting to push my bullets out to with in .015 of the lands, This did help considerably.. I went from shooting roughly inch to inch and half groups to now with some powder work I am down to half in groups most of the time. My dad had some money left over from his retirement and he wanted something to do with me that we both could enjoy.. so.. we went 70/30 on some tools.. Sinclair concentricity gauge, K&M Neck turner, Annealez annealer, Uniquetek floating tool heads for the Dillon 550, and then also a gempro 250.. I really have not had a chance to go and test out the brass we are still in the process of slowly working through the brass and getting everything, sized, mandrel expanded, annealed, trimmed, deburred, neck turned and then get into the powder side of things.. Interesting, I ran some numbers when we received the gempro 250 since its accurate down to .002 grains I tested out 20 rounds that i had previously loaded on the Hornady powder thrower.. and found most to be close but I did have a variance of almost half a grain most of the time..

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Good shooting man. Thanks for sharing..

 

[bsa1917hunter]

As luck would have it, I was recently given a nearly new Hornady Concentricity gauge. Tonight I grabbed one of my reloads and tested it. Came out at .001". So I tested a couple more. Ended up testing 10 and most were .002" or less. Two were .003".
It was nice to verify that part of the process is working out well.

orygun, when it tests out like that, you know you are doing your part and so is your equipment. I've used my concentricity gauge to actually help set up my seater dies for minimal run-out: Less than .003" for your run of the mill RCBS FL set you can buy at bi-mart...

 

[orygun]

Less than .003" for your run of the mill RCBS FL set you can buy at bi-mart...

That's exactly what dies I use, only I don't set the shoulder back.

 

[bsa1917hunter]

That's exactly what dies I use, only I don't set the shoulder back.

Yep, I PFLS (with about .003" shoulder bump back) with my sizing die and set the seater just right... Run out looks great that way. Pretty amazing what you can do with a cheap set of dies... . I do like to bump the shoulder back, just enough so there's a slight resistance when I close the bolt. I also need my ammo to be 100% reliable for the hunting I do...

 

[woody06]

Gee, and I thought I was a serious reloader because I weigh each powder charge for rifle and have on occasion weighed each bullet and sorted them into groups by weight. You guys are making me feel like a neophyte.