Concentricity - how big of a difference?

[Burr]

Since I'm a bit new to the board - I'll start with a bit of explanation. I've reloaded ammo for decades, don't shoot competitively, shoot for hobby at the range and hunting. Through those decades I've done extensive load workup with components - but I've never considered myself or my procedures to be at an advanced level.

Which brings me to the explanation - current efforts are to learn some of the finer details of reloading, and what improvements can I make by adding steps that I've previously not performed. In that process - I'm just starting the process of neck turning, haven't really gotten a firm plan for neck tension, getting the tools to measure seating depth off the ogive instead of the meplat, and looking into concentricity of loaded rounds.

I just purchased the Hornady bullet concentricity gauge, and took some of my loaded rounds to measure runout. Not sure if I'm surprised, but measurements on my loaded rounds are showing a level of error that I'm taking some steps to correct.

I grabbed some of my 22-250 handloads, and I get .010-.012 run out pretty consistently, up to .015-.016 on the worst runout. Nothing better than .009. I'm able to adjust the runout down to .001-.002 with Hornady tool.

My question is - how big of a difference does this level of runout make on a target? Has anyone ever tested loaded rounds to compare the grouping potential? Is this level of "not precise" in my reloads .5MOA, more, less?

I know, I could go to the range and fire them to find out myself, problem is I rebarrelled my 22-250 to a 250AI so I don't have the gun to shoot for the results. Plus, it's raining at the moment, so my shooting time is on the forum. I was just working with these cartridges because I am going to pull the bullets and resize the brass for the 250AI. A replacement 22-250 is off into the future.

Any comments or suggestions on reloading for accuracy for me that has reloaded extensively, but not become familiar with advanced techniques are welcome. Through reading these forums and other articles I am tooling up and looking into things like neck turning, bullet concentricity, and I intend to get either some Lee Collet Dies or bushing dies to see if I can tighten up groups, and maybe accomplish better accuracy for longer distance shooting. Is this a good area for me to move my reloading skills into a more advanced level? Or should I focus on something else?

[Balljoint]

From what I have seen in my own reloads is that bullet concenricity will affect bullet flight at longer ranges say 400 to infinity, at 100 yrds will not affect bullet flight

[yobuck]

First off dont go pulling any bullets on your existing 22 250s. Just shoot them in the new chamber and their good to go.
Then resize with your new ai dies. Neck turning as a rule isnt necessary in factory chambers. Fact is you can ruin brass
by turning them for factory chambers if your not very carefull. As for your loading process, if (your) satisfied with how your guns shoot,
then behappy with the way you currently load. If you are or intend becoming a serious competetive shooter, then each thing you do
could affect your scores. But even then, the order of priorities would be a gun worthy of the extra effort spent loading.
If you and your guns are capable of inch or better groups consistantly, then your good to go even for long range shooting.
That would equal out to about 10 inches at 1000. Fact is most guys here including me cant shoot that good on a consistant basis.

[jonbearman]

One thing you could check by pulling a half dozen bullets is to see if they peeled going in the case or are there scratches all over the pulled ones. After you do that I can give you some more advice.

[Burr]

One thing you could check by pulling a half dozen bullets is to see if they peeled going in the case or are there scratches all over the pulled ones. After you do that I can give you some more advice.

Bullets are not scratched on these, but I'd rather you started with peeled/scratched bullets, as I've had that before on trimmed brass. There's a good chance the bullets I pulled were loaded in new brass, I used a limited number of brass working up a load, then loaded the all brass I had.

yobuck- part of what your saying is why I'm working with the 250AI to see what I can do for accuracy. The gun is a varmit contour Shilen barrel, where most of my guns have sporter weight factory barrels. I also hear you on the shooter being able to measure up. I'll say in the past, when I've been doing a lot of shooting, I know I get to the point of being capable, mostly through practice and repition. I am going to meet with a competitive shooter to discuss the finer points of shooting technique - I've never taught those things by another - so looking forward to that.

Shoot a .22 cal bullet in a .257 bore? I had not planned on that.

[LongRange]

My suggestion is to buy a forster BR full length die(send it in to have the neck honed to your desired neck tension)a wilson hand die and an arbor press then you wont need to worry about concentricity.IMHO...and personal experience...the Hornady concentricity gauge will cause you more issues than you already have because as your chacing and adjusting run out your tweaking the necks and causing inconsistent neck tensions which cause fliers and higher extreme spreads especially if your adjusting up to .016 of run out. I have a hornady concentricity gauge that hasnt been used in about 4yrs...i talked to several old BR guys and most all said the same thing"buy better dies"! And one told me"you dont shoot BR dont worry about run out"he also told me to load 10 rounds exactly the same and adjust run out on 5 and shoot all 10 over a chrony....the 5 adjusted had a 35fps spread the 5 not adjusted had a 20fps spread.
Another suguestion is to do everything you can to eliminate cartage inconsistencies, do everything EXACTLY the same every time you load and most of all work on your trigger pull and position behind your riffle.

[mike21]

Bullets are not scratched on these, but I'd rather you started with peeled/scratched bullets, as I've had that before on trimmed brass. There's a good chance the bullets I pulled were loaded in new brass, I used a limited number of brass working up a load, then loaded the all brass I had.

yobuck- part of what your saying is why I'm working with the 250AI to see what I can do for accuracy. The gun is a varmit contour Shilen barrel, where most of my guns have sporter weight factory barrels. I also hear you on the shooter being able to measure up. I'll say in the past, when I've been doing a lot of shooting, I know I get to the point of being capable, mostly through practice and repition. I am going to meet with a competitive shooter to discuss the finer points of shooting technique - I've never taught those things by another - so looking forward to that.

Shoot a .22 cal bullet in a .257 bore? I had not planned on that.

My guess is that yobuck is under the impression your new caliber is 22-250AI. I'm a little confused also, since you mention 250AI and .257 bore in the above post. What is the caliber of the Shilen barrel?

Interesting read, thanks for posting.

[jonbearman]

All 3 are from the same parent cartridge, 250 savage so they should chamber and interchange only to fire form. The bullet being undersized shoul just rattle down the bore and form a perfect 250AI cartridge. The bullet being under sized wont stabilize but who cares as you need a perfectly formed case and you aren't shooting a group.

[barrel-nut]

FWIW, I have two concentricity gauges, a Sinclair and the Hornady mentioned above. Almost without fail, they give very different readings. A round that has less than .001 on one might have .005 on the other. This is caused by the fact that the two gauges use different points of reference when spinning the case. The Hornady uses the case head on one end and the bullet tip on the other to support the round, with the indicator placed between the two points. I've found that this tends to give lower readings. The Sinclair supports the case on two non-rotating bearings that you position under the body of the case. The indicator is then positioned out over the bullet or the neck. This method tends to give higher indicated runout readings. Most strangely, as I stated before, a round that is straight on one gauge may be significantly off on the other. I agree with LongRange that excessive "straightening" is probably counterproductive. If the round is in really bad shape from the outset, pushing really hard on the neck is not going to solve anything.
Also, I sort my rounds for concentricity and mark the best ones and place them in the front row of the fifty-round ammo box. The funky ones go to the back of the box. Here's another weird thing- on many occasions I've shot just as good groups with the "banana" rounds as I have with the straight ones. So go figure. I can't explain it.
None of the short-range benchrest guys I've talked to- and admittedly that's only a few- actually make any attempt to measure runout. They all seem to believe that their rounds are inherently perfect due to their dies/arbor presses. Maybe. I'd love to actually measure a few of theirs just to see. Never had any offers to actually measure though.

[barrel-nut]

Double post

[yobuck]

Yep, my bad, didnt pick up on the 250 ai and assumed 22 250.
Mind you i have the runout gauge and also neck turning tools.
But i seem to be limited with my own ability to the point it dosent matter.
I simply turn the case a couple times during the seating process and it works for me.
And as long as i hit most of the rocks i shoot at im happy even if its not on the first shot.
Ive known a few long range target shooters who simply mark the head of the case at
the high spot for runout. Then single feed each round into the gun with the mark alligned
the same way. They seem to think consistancy is important more so than perfect.
Thats fine for casual shooting, but when the hearts pumping faster those type things are hard to remember.

[Burr]

Mike21 - 250AI is the 250-3000 Savage Ackley Improved, 40 deg shoulder.

I intend to expand the necks on 22-250 cases to make brass for the 250AI. I think I'll still pull the bullets instead of "rattle" them down a new custom barrel to resize the brass.

So, I'm gathering from the posts - while the Hornady tool is measuring something - if I intend to fix it - my best method is to prevent the issue from happening in the first place by using different/better forming and seating dies - which gives me a direction to go. With Forster - is their method to take the measurements from the reamer that was used to make my barrel, or shoot/reload a couple cases 3X and send the formed cases in to make the resizing die? Or, do the obvious, call Forster and ask them, lol...

Same approach as LongRange suggests - use the gauge to measure, identify current status, find a way to prevent it from happening, identify if it is an issue at all, and once "fixed" the runout gauge becomes a tool that doesn't get used.

As many have stated, I'm not sure what difference I'll be finding, but with all the reloading I do, I don't mind trying the different things and finding out from my own experience how much of a difference these things make. Compared to my other hobbies, reloading is rather thrifty. Putting gas in my 60 gallon boat tank is more than a concentricity gauge and custom dies. So I know it may not be a cost effective endeavor for a non-competitor - rather an interesting, educational one that builds on the handloading experience I have enjoyed over the years.

[LongRange]

you CAN have custom dies made but at about $200 bucks per die...forster is not making custom dies right now as far as i know but you may want to call them and check.
the wilson hand die can be sent in to wilson with a few fired cases and they will hone it to match your chamber or fired cases.

now i have not been loading as a lot of you guys(almost 10yrs)but i can tell you i started by just shooting until the brass was hard to chamber then id bump the shoulders with a redding body die and carry on...never tumbled,lightly cleaned primer pockets and necks. as i got more into it and searching for long range accuracy and most of all consistency things changed and i can tell you first hand that the more detail you give to your reloading the more accurate and consistent your loads will be i dont care what anyone says its a fact.
now you can spend ENDLESS money chasing accuracy but the 3 most important factors in accuracy(IMHO)are first...the shooter...second the riffle and third the hand loads..so if you take as many variables out of your ammo and riffle as you can then that leaves one thing the shooter. up until about 5yrs ago loading was fun now its a part time job LOL!!
like i said buy a forster full length die send it in and have the neck honed to your desired neck tension and set it up to bump the shoulders back .001-.002 and use it EVERY time you fire your brass...get a wilson hand die and an arbor press and dont worry about concentricity as your not going to load it any straighter unless you spend some serious coin on dies...trim your necks EVERY time and do yourself a favor and get a stainless steel tumbler and tumble your brass every time as well. and last if you dont now learn how to anneal your brass...it will help when looking for low ES's and consistency. as far as turning necks goes...i do it but just to clean the necks up as i dont have a tight neck chamber and also to take that variable out.

like i said the accuracy hole is deep how far in you want to venture is up to you LOL.

[earl39]

One thing to remember if you do as Longrange says and get a wilson and have it honed for neck tension is to get that consistent neck tension you have to turn your necks to a uniform thickness. Different thickness necks means different amounts of neck tension unless you are using an expander button and if so why spend the money to get a die honed out.

[BillPa]

- while the Hornady tool is measuring something

That "something" is TIR, "Total Indicated Runout". Actual off center RO is 1/2 TIR. For instance, if TIR is .010" the off center is .005".

By rights the tool should use two indicators, one positioned at the neck of the case and one near the tip. A bullet could be running true in the middle but be out on both ends in opposite directions pivoting on the middle like a seesaw.:p

Bill

[yobuck]

One thing to remember if you do as Longrange says and get a wilson and have it honed for neck tension is to get that consistent neck tension you have to turn your necks to a uniform thickness. Different thickness necks means different amounts of neck tension unless you are using an expander button and if so why spend the money to get a die honed out.

? I guess an old guy who dosent read very well cant be expected to understand very well either.
Anyway Burr whats your favorite way to catch walleyes?

[earl39]

One old guy to another yobuck, does that mean i didn't understand something or you didn't understand what i said?

[DanSavage]

The gauge I use references off the case body and indicates a little bit back from the bullet tip,, in theory that is what you want. When I started chasing my run out issues I found out that it was all introduced at the bullet seating process . I upgraded my seating die to the Redding competition seater die and runout improved big time,and so did my competition scores.Now I don't even bother checking runout . When a guy straightens a round he changes neck tension . .005 or less is good enough for me to be quite competitive.

[LongRange]

One thing to remember if you do as Longrange says and get a wilson and have it honed for neck tension is to get that consistent neck tension you have to turn your necks to a uniform thickness. Different thickness necks means different amounts of neck tension unless you are using an expander button and if so why spend the money to get a die honed out.

You can have the wilson hand die...which is a seater die im referring to... honed to fit your chamber size by sending in fired cases...the forster FL die can be sent in to have the neck honed to your dimensions so that your not over working the necks when sizing...i just sent my new forster FL die in to have the neck opened up to .285 and have 3 under sized expander balls made so that i can vary neck tension.
If he FL resizes every time there is no need to hone the wilson hand die.... if only neck sizing the wilson will need to be opened up a bit. I just bought the forster FL die to eliminate 2 steps in my reloading.

[LongRange]

The gauge I use references off the case body and indicates a little bit back from the bullet tip,, in theory that is what you want. When I started chasing my run out issues I found out that it was all introduced at the bullet seating process . I upgraded my seating die to the Redding competition seater die and runout improved big time,and so did my competition scores.Now I don't even bother checking runout . When a guy straightens a round he changes neck tension . .005 or less is good enough for me to be quite competitive.


Ive owned redding dies since day one of my reloading and really like them but after using the wilson and an arbor press i rarely use the reddings anymore and when i get my forster FL die back ill most likely put my redding dies up for sale.