Concentricity/'run-out' gauges - any use?

Dalua

Well-Known Member
The Hornady concentricity gauge is nice and red, like my Hornady case-trimmer.

Apart from that obvious attraction,
1. Is a concentricity gauge for reloads useful?
2. If it is, is the Hornady one a reasonable one to buy?

Any experiences/opinions welcome!
 
The Hornady concentricity gauge is nice and red, like my Hornady case-trimmer.

Apart from that obvious attraction,
1. Is a concentricity gauge for reloads useful?
2. If it is, is the Hornady one a reasonable one to buy?

Any experiences/opinions welcome!

I bought the Hornady on a lark and on sale and it is interesting but the results were inconclusive as to straightening out the "crooked" rounds. I flare the case mouth of CF rounds so all of my loads fall inside the .003" run put limit set by Hornady as being acceptable. Mine has been on the shelf for three months now without being used. Were I you, I'd save my money.~Muir
 
well I fell for the beautiful gucci piece of precision runout measurement from a swiss co. that had gone out of business (there is a clue there) and I have found it to be lovely, nicely made and almost entirely pointless despite the fitted case and neat detailed instructions.
Its great for instilling confidence that your homeloads have been seated concentrically...but as to straightening ammo...I'd have been better spending the money on ...well almost anything else really
Unless you are loading to shoot mega range target I wouldnt bother
 
I think perhaps I'll not bother!

Good for you but I'll tell you this it made me wonder (and correct) about my reloading technique and brass quality.
I use the RCBS version and ran a few of my 22BR (neck turned) rounds through it for a "laugh" and got under 1 thou (or +/- less than a division) run out on the ogive.
I then ran some of my 22-250 hunting loads which'll group five shots in under 1/2 MOA and they weren't so good...7 thou run out.
So, investigated a little and the necks are not very concentric (Norman, PPU and Winchester) and it prompted me to turn a few with my existing neck turner.
I've just "blown" these out and will reload for a proper range test to see if it's worth it...

I guess, as Dirty Harry said, "A man has to know his limitations" but I'd also ask what level are you aiming for? Might not be worth it but you might learn something about yourself and the kit you use. I like to think that I can still learn something new every day. Some people like to think they already know everything but that must be a dull life.

Got a mate you could borrow one from?
Take a round to the shop and try it out? :) Bit cheeky but you never know!
 
It's a but like an expensive equivalent of an OAL gauge: you use it when you get some new dies, brass or bullets, usually find out that everything is hunky-dory and doesn't need straightening, and then it goes back into its box for an indefinite spell.

There's some peace of mind to be had from eliminating (or identifying) run-out as a possible factor in group size but I certainly don't check each batch of ammo when using components/tools that are a known quantity.

IME, when trying to hit small things at long range, minimising run-out is worth doing, but for "normal" shooting the appeal has more to do with inquisitiveness than practicality, let alone need, though there may be some psychological advantage derived from knowing your ammo is impeccably concentric.

I'm naturally inquisitive, and like having my confidence massaged by such measurements, so I'm keeping mine!
 
Good for you but I'll tell you this it made me wonder (and correct) about my reloading technique and brass quality.
I use the RCBS version and ran a few of my 22BR (neck turned) rounds through it for a "laugh" and got under 1 thou (or +/- less than a division) run out on the ogive.
I then ran some of my 22-250 hunting loads which'll group five shots in under 1/2 MOA and they weren't so good...7 thou run out.
So, investigated a little and the necks are not very concentric (Norman, PPU and Winchester) and it prompted me to turn a few with my existing neck turner.
I've just "blown" these out and will reload for a proper range test to see if it's worth it...

I guess, as Dirty Harry said, "A man has to know his limitations" but I'd also ask what level are you aiming for? Might not be worth it but you might learn something about yourself and the kit you use. I like to think that I can still learn something new every day. Some people like to think they already know everything but that must be a dull life.

Got a mate you could borrow one from?
Take a round to the shop and try it out? :) Bit cheeky but you never know!

It's that damned accuracy weasel.
You catch the thing by the neck and are proud of your efforts. Then you say, I'm faster than that! I can do it better! And let the little ba$tard go so you can try it again. A lot of times that doesn't work out the way you plan. When I catch the thing I hang on.

Be wary of concentricity gauges/tools that rotate the case on the body of the case with the bullet end free-wheeling. There is no saying that your case is round (concentric to it's center line) to begin with; especially if it's a neck sized case. One of the reasons the Hornady unit caught my eye at all is because it centers on the rim and the tip of the bullet. An inexpensive unit, and one I used for years, is made by ordering a cheap, ground machinists V-Block, a magnetic base and a dial indicator. It works well but should be used with FL resized cases or those fired in a custom chamber.

Whenever I think of concentricity I'm drawn to the image of that first nano second of ignition where a flow of virgin gasses pops the neck loose from the bullet and the bullet is suspended between the flow of gasses passing on each side... right before it's jammed into the rifling and sent down the barrel.

Gives me a headache.~Muir
 
It's that damned accuracy weasel.

It is indeed but I don't like to waste time (49 this year) and so a "duff round" is a wasted round. I use the tool to check that I've stuck to my rules and not become lazy.

You're right (sort of :)) on the case POV but it has dawned on my that if you adhere to the "not quite fully resized" school of reloading (Was some US gun writer years ago (1980s maybe) that wrote a good piece that I followed) then you've a case that's quite close to the chamber dimensions and that the neck (once ironed out by it's first firing after neck turning) ought (only "ought" not "will") to be nice and concentric with it provided the manfacturer or rifle maker was doing their job.

Sounds like your V-block is a nicer version (what a "real" engineer would do given the choice) of the RCBS piece of tat I have and quite similar to what a machinist friend of mine did.

I honestly feel I've enough "accuracy" to engage what I need to with but I loathe (I'm a scientist by profession) any deviations from the norm and the odd unexplained random is enough to drive me nuts!
 
It is indeed but I don't like to waste time (49 this year) and so a "duff round" is a wasted round. I use the tool to check that I've stuck to my rules and not become lazy.

You're right (sort of :)) on the case POV but it has dawned on my that if you adhere to the "not quite fully resized" school of reloading (Was some US gun writer years ago (1980s maybe) that wrote a good piece that I followed) then you've a case that's quite close to the chamber dimensions and that the neck (once ironed out by it's first firing after neck turning) ought (only "ought" not "will") to be nice and concentric with it provided the manfacturer or rifle maker was doing their job.

Sounds like your V-block is a nicer version (what a "real" engineer would do given the choice) of the RCBS piece of tat I have and quite similar to what a machinist friend of mine did.

I honestly feel I've enough "accuracy" to engage what I need to with but I loathe (I'm a scientist by profession) any deviations from the norm and the odd unexplained random is enough to drive me nuts!

By the sounds of that 22-250 load you are doing nothing wrong in your reloading and that .007" run-out isn't an issue in your particular gun! I have found that lightly flaring the case neck and seating the bullet as deeply as is practical reduces run-out quite a bit -when I care to check them, that is. The worst "run-out" or misalignment I've had was with a 9.3x57. A cocked expander ball was pulling the necks so far off center that a loaded round wouldn't chamber. The case was visibly bent at the neck/shoulder junction. Here's the strange part: The rounds that would chamber shot as well as I could hold at 50M using iron sights: Most often, one ragged hole. As I said, it gives me a headache sometimes.~Muir
 
By the sounds of that 22-250 load you are doing nothing wrong in your reloading...


Yes, the old Lyman M-Die trick…I must try it out again.

Oh, I know that but always aspire to better. I always like to come first on the range.

BTW sold my 22BR as I found it "boring" since all I needed to do was prime, drop powder in the (neck turned, primer pocket milled and deburred) cases and pop a bullet on...and it'd shoot a dream no matter what. My mate's very pleased with his new tool...he’s got 500 lovely Lapua cases to play with (I’ve owned two 22BR rigs).

I'm just curious what the 22-250 will do with better case tolerances...just curious, not driven bonkers, you know?
 
Yes, the old Lyman M-Die trick…I must try it out again.

Oh, I know that but always aspire to better. I always like to come first on the range.

BTW sold my 22BR as I found it "boring" since all I needed to do was prime, drop powder in the (neck turned, primer pocket milled and deburred) cases and pop a bullet on...and it'd shoot a dream no matter what. My mate's very pleased with his new tool...he’s got 500 lovely Lapua cases to play with (I’ve owned two 22BR rigs).

I'm just curious what the 22-250 will do with better case tolerances...just curious, not driven bonkers, you know?

I understand. I do it all the time. Have fun.~Muir
 
Its great for instilling confidence that your homeloads have been seated concentrically...but as to straightening ammo...I'd have been better spending the money on ...well almost anything else really

I don't think they are intended for correcting eccentric cases, just detecting them. I have the RCBS Case Master use it to detect and cull eccentric cases. In short, with new brass, I measure the brass about 0.010" back from the case mouth after full length resizing, Anything that has more than 0.003" eccentricity gets culls, unless it's for my Enfield No 4 and then I'm less fussy. One thing it revealed is as follows.

I neck resized 100 fired Lapua 7.62x54R cases (I have a Dragunov). Lapua brass is some of the best available. I measured all 100. The neck runout was up to 0.008" in most lot of them. One or two were up 0.012" runout. Alarmed, I full length resized the lot and measured them again. The neck runout dropped to around 0.003" with a handful at 0.005". Many people believe that neck resizing produces "more accurate" brass because it's "fire formed to your chamber" etc. Well, not in this case. Clearly the NR die is defective but without measuring neck runout, I would never have discovered it.

-JMS
 
I recently got hold of the Hornady lock-n-load concentricity tool. I really can't be arsed spending hours just to rattle up a handful of rounds so provided I start with square &trimmed cases, I can get on in the knowledge that the rounds will be true.

​My groups have tightened noticeably but whether it's due to the elimination of possible run-out or a greater confidence in my home loads? I'm happy with mine but it has made me more anal. I recently bought a box of Geco rounds and tested a few. I ended up truing up the whole box.
 
I don't think they are intended for correcting eccentric cases, just detecting them. I have the RCBS Case Master use it to detect and cull eccentric cases. In short, with new brass, I measure the brass about 0.010" back from the case mouth after full length resizing, Anything that has more than 0.003" eccentricity gets culls, unless it's for my Enfield No 4 and then I'm less fussy. One thing it revealed is as follows.

I neck resized 100 fired Lapua 7.62x54R cases (I have a Dragunov). Lapua brass is some of the best available. I measured all 100. The neck runout was up to 0.008" in most lot of them. One or two were up 0.012" runout. Alarmed, I full length resized the lot and measured them again. The neck runout dropped to around 0.003" with a handful at 0.005". Many people believe that neck resizing produces "more accurate" brass because it's "fire formed to your chamber" etc. Well, not in this case. Clearly the NR die is defective but without measuring neck runout, I would never have discovered it.

-JMS

It's not the Neck die being defective. It's your case being out of round after being fired: Cases don't always expand uniformly in the chamber. You noted that Fl resizing cured it to an extent. And frankly, a Dragunov? Not exactly a match spec chamber, I'm guessing.

The Hornady tool does straighten out "crooked" bullet seating and is advertized as such. A much better method is to find a way to cure the run out before seating. I found that cases that are flared gently with the Lee Universal Expander Die give less than .003" run out on a seated bullet -which is where Hornady recommends not worrying about it.

In a factory chamber it's hardly worth fussing over.
I was discussing this with one of my shooting buddies last night and he related sitting at his kitchen table loading his ammo bag with some Lake City Match .308. A few rounds fell over and rolled towards him and he noticed that the bullets wobbled as the case rolled. Curious, he took a handful of the wobbly rounds behind the barn and proceeded to shoot 12 ounce soda cans at 300M from his Remington 700. I related my own story with the 9.3x57 in an earlier post. Extreme run out had no effect on accuracy at iron sight distances. ~Muir
 
I don't think they are intended for correcting eccentric cases, just detecting them. -JMS

The kit I'm referring to isnt a case guage type tool but is intended to measure/correct runout in loaded rounds where the head may 'off'. The dial guage has a small pad which is used to determine runout on the buller rather than the case.
 
Back
Top