Recently bought a Sinclair concentricity gauge. Its been eye-opening. I wondered why my 257 Robts Hornady Superformance still shot so crappy in my bedded Montana. They have runout from 0.000 to 0.010. You can see some of the bullets wobble, and it ain't a little bit.

So, spent some time this AM sorting cases. I'm doing final load work-ups and picked only those cases with 0.0015 or less runout to use. I checked some of my other loaded handloads and they are fairly straight - most at ~ 0.002 or less. I did come across a couple of 0.005-6 which I think explains a few of my flyers I get. I'm hoping any way. Can't tell you how tired I am of shooting great 3-5 shot groups with 2-4 tight and 1 out an inch or so, making a nice 1.5-1.75" group. All this time I thought it was me

Anywho - how do you guys straighten loaded ammo? I know Hornady has a system but I'm looking for the redneck ingenuity method.

Thanks.

BTW: my Redding dies turn out some really straight cases. I have a couple of RCBS that do but have a couple that may need some investigation as most of the big handful of cases I measured had necks with up to 0.005 runout. Gonna be pretty hard to get bullet concentric when it starts out 0.005 crooked.........

For redneck application I had caliber size holes drilled in my wood work bench then I became sophisticated and purchased a TruAngle Tool.

http://www.trutool-equipment.com/

^^^^^

Works like a champ. Once you get the dies and technique nailed down that produces concentric rounds, it'll sit in the corner but nice to have (and ready for the next excursion into non-concentric ammo).

TruAngle. Done.

The TruAngle tool is the best solution I've found, because unlike other bullet-straighteners it bends the case neck and doesn't just push the bullet. Just pushing the bullet results in erratic neck tension, which doesn't help accuracy either.

John can comment on this since he is the one who alerted me to run out years ago through his writings.

But anyway I started sorting cases and loaded ammo based on .005 or less being acceptable for BG rifles. I understand wanting to get factory or hand loads as close to perfection as possible but discovered that in many hunting rifles groups didn't improve a whole lot if I shot the stuff way under .005.

Maybe target or varmint rifles but for BG sorting .005 and under did a great job of eliminating the funky flyers.

Had a couple of pre 64 M70 30/06's that would simply bug hole with this treatment. I think that run out is the real culprit with a lot of rifles that don't group well.


One question I have is that the True Angle literature says run out is a by product of brass too thin on one side of the neck. I can understand that but can't reconcile fired brass that comes out of a chamber virtually perfect, but has excessive run out after resizing? I always figured sizing and imperfect seating was the culprit?

The 60K psi of firing form fitted the outside of the brass, where you measure runout, to the inside of the chamber. If the chamber is good then so will be the outside of the brass. (This assumes brass that isn't really bad.)

OK, now suppose the cases come out of the chamber reading straight on the outside. Also suppose the conventional size die is perfect, but the brass is thicker/thinner on one side of the neck. On the upstroke of the press ram the outside of the brass is formed to the contour of the die chamber. The outside of the brass is concentric at this time. But the hole inside the neck isn't. On the down stroke the expander, which is assumed perfectly centered in the perfect die, expands the hole and in the process tries to pull it to the center line. Voila, crooked brass.

Never had the need for a straightener once I added neck turning to the first time prep of new brass. AND the use of Lee Collet dies for neck sizing.

https://dl.dropboxusercontent.com/u/47141769/Runout.jpg (link shows full size)

the case on the right as you can see isn't neck turned and has a 0.003 thicker neck on one side. BUT using the Lee Collet keeps the neck concentric even though there's uneven neck thickness.

the case on the left has been turned and will result in straight rounds for the rest of their useful life and the reason I include neck turning as one of THE most important steps in first time brass prep! I never turn to a specific size as it's not necessary since no bushings are used (for the collect die).

and to the OP, when my concentricity gauge showed up it was the worst day in my handloading career! lol completely ruined my day once I started checking rounds!

just my $0.02!

Bobin brings up a good point - what is acceptable runout? I've always been of the opinion that anything less than 0.003 measured on the bullet ogive or slightly forward is acceptable. I've never owned a runout gauge but have used them. My basic test was roll a cartridge across glass - if can see wobble its too much. I'd guess that was about 0.005" runout. I tried it today using measurements and I can see runout greater than 0.005 using something very flat. Used my granite counter top this AM.

This is going to open a whole new level of geekery for me............

I do love handloading every bit as much as shooting!

I wasn't totally joking when I told people at the range I go out there and shoot them so I can go back to the shop and load them again.

It is an endless circle! Do I load to shoot, or shoot to load! It's never really clear!

Yes

MM: Thanks for that explanation. Makes sense.


For me the really bad stuff was well over .005,hand loads or factory.

One time i took the 30/06 150 Fusion factory ammo and sorted .005 or smaller,shot some tiny groups and hung them at the LGS. They sold out of 150 Fusions very fast.

As I recall I had only 6-7 culls from a box of 20.

I've measured a lot of factory ammo including federal GM match that was .006 or greater in runout !

A shooter @ Camp Perry in the late 50's or early 60's wrote an article which was published in the NRA's Reloading Manual of that era, regarding runout and effect on accuracy. I don't have access to those books at the moment but if memory serves, he determined that .002" runout was the magical dividing line. He also determined that over .0045" runout it didn't get any worse for accuracy. That's part of the reason I don't turn necks (which is what I hate to do most about reloading!) and use brass that has less than .0015" uniformity in the necks.

The TruAngle tool looks interesting. Can someone explain to me how a you know how to insert the cartridge/which spot to apply pressure to in order to straighten it? Thanks, John

Use a Sharpie to mark the cartridge on the high side of the wobble.

Stick the front end of the round into the appropriate size hole and bend it so as to push the bullet high side toward the center line.

Thanks!

Rifle magazine also did a write-up on concentricity and the affect it has on accuracy. I have one of these concentricity tools (Brown Precision little wiggler) that reads run-out and also corrects for it as well. I've noticed that straightened ammo shoots much better than ammo that has more than .004" TIR:

Brown precision little wiggler. Rifle magazine article on concentricity..

I played this game years ago when I got into bench rest shooting, but since then let it go. What made me stop was having ammo sorted with run out, shot them out of my bench gun and sh&t didn't make a bit of difference. Gun was grouping in the .1's just like the sorted rounds, from that day forward I stopped doing it. And if that didn't make that much difference in a bench gun I sure it wont make any difference in a factory gun. You guys can flame me on this but I have a lot of custom guns that will shoot bug holes without doing the concentric game. If I can put 10 shots in a group that measures .1 or .2 how much better can it get.

Helpful and interesting. What dies, etc. do you use to build your rounds...that'll make a difference as I understand it.

ALL dies are a crap shoot because of the minute differences in all, and how they match to the chamber for which the round will be used. When dies are made the setup of the body and the wear in the reamer being used, and then the warpage, if any, in their heat treatment, ALL affect them. I use dies from most manufacturers and I have had good luck with cheapo's and bad luck with expensive ones. The features of a particular manufacturer usually propel you to one or the other, but you're still rolling the dice. I've got some great Lyman and Lee dies that really work for a particular barrel, and the Forsters and Reddings can't match them. I've also had bad luck with all and not necessarily the fault of the maker. That's the reason I have 43 different die sets!

Some of mine here:

Good post, Bob.

gemby,

How much runout on the benchrest rounds you were testing?

John that's was back in the 80's, and really don't remember. But when shooting them and them grouping like they were I said to myself why even bother. I sold my gauge and never checked them again. I use Redding bushing neck die, body die when the shoulder needs bumped back and Forester seating die. Beside my benchrest guns I have many custom sporter, varmint, and long range guns that shoot bug holes. Greg

Bending a bullet or neck back into a straight position treats the symptom, not the problem. The problem that leads to non-concentric ammo is a combination of brass prep and tools used that change the shape of the brass. Could also add in reloading technique.

If your reloading technique yields "consistent" results - regardless if concentric or crooked, then you should feel confident your reloading techniques being used are solid, it's just identifying steps you are not taking (brass prep) and a critical eye on your forming and seating dies.

That is if you believe concentric ammo is worth pursuing. I do believe it contributes. Any one step may not be measurable, but all the added steps are cumulative - which is where you will see an improvement.

If you choose to bypass neck turning - it's my opinion you're limited to a Lee Collet Die, and a good seating die that supports the whole case when seating. Neck turning does not negate the positive impacts of the above tools either.

Choosing the right combination of components contributes as well, think barrel harmonics, low SD and low ES. If one reload is 100 fps faster than the next - how can it possibly have the same point of impact very far down the range?

If the bullet comes out the end of the barrel the same every time, it will hit the same place on the target. It's just that simple.

Of course - this is all just my opinion, and your mileage may vary.

tagging this thread.

Greg,

Thanks for the info, which explains a lot.

There's no real point in using a concentricity gauge in really accurate rifles (especially custom-chambered with a minimal reamer) when using good dies. I don't bother in my own benchrest rifle, either, because any tiny differences in run-out with neck-turned cases loaded in Redding Competition dies don't result in any discernible accuracy differences. I also use good dies of various sorts, combined with good brass, in my varmint rifles, because I am NOT going to check every damn one of 1000 rounds of prairie dog ammo. But we're talking about differences of maybe .001" or at most .002" in concentricity.

On the other hand, concentricity gauges are VERY useful in many other rifles, especially typical factory big game rifles with looser chambers and barrels, especially when using standard dies. Partly this is because the difference in how much more bullet run-out can result from standard dies.

I started using a gauge because of mysteries in how well big game rifles shot with various kinds of ammo or even bullets. My first was an RCBS Casemaster, and the instructions suggested no more than .005" of bullet runout, measured about .1 inch in front of the case mouth, for big game rifles, and no more than .003" for varmint rifles. Over the years I found those recommendations to be pretty much spot-on, especially with factory rifles--but they're obviously many times what we might encounter with match-type dies and neck-turned brass.

A concentricity gauge not only allows a handloader to figure out which rounds might be causing fliers in his .270 or .338, but to pinpoint the problem in the loading process that causes bullets to have too much runout.

The RCBS Casemaster even revealed why one of my .270's apparently "liked" 150-grain Hornady Spire points so much it would group them in around an inch at 300 yards. This was a Remington 700 ADL with no modifications other than adjusting the trigger, bedding the action, and free-floating the barrel. I never could get similar accuracy out of any other bullet in that rifle, even Sierras, and it turned out the seating die apparently fit the Spire Point ogive closer than tangential ogives in Sierras--so seated the Hornadys much straighter, even in ordinary brass.

Have also used a concentricity gauge to turn ordinary sizing dies into what are essentially Forster dies, by raising the expander ball inside the die. The ball, however, often must be adjusted to a particular point to get the most benefit, and the concentricity gauge reveals that point. Have also used it to make other simple die or loading process modifications that improved accuracy considerably.

Have also used a concentricity gauge to sort factory ammo, with very definite results. Once had a custom 7x57 with a Hart barrel and minimum chamber, and came across a very good deal on a bunch of Hornadys now-discontinued Light Magnum loads with the 139 boattail Spire Point. I sorted them into three batches, one with runout up to .003", another up to .005", and the third over .005". The .003" batch would consistently shoot into .5 or a little more, the .005" batch into around an inch, and the over-.005" batch into 1.5".

As a result of long use of concentricity gauges, most of the time I don't need to measure the run-out on loaded ammo, but do tend to measure it on test loads with new bullets and brass--just to make sure I'm testing the load at the range, and not run-out. But if there are a few rounds with bullets slightly out of line, I use the TruAngle tool to straighten them. Have found through that experimentation that it's pretty much a waste to try to straighten rounds more than .002" over specs, but less than that certainly works. Again, the concentricity gauge revealed that information.

Now, not much of this may be of interest to you, because of the types of dies and rifles you use. But it is of interest to many handloaders who use average ammo in average rifles, where a concenctricity gauge definitely can make a big difference.

and there's no other tool I know of that will measure the wall thickness down at the web where separation may take place!

It may not give me a number, but a straightened out paper clip with an end bent into a short, 90 degree hook tells me what's going on down there.

I've done a similar thing with 7.62x51 LC match ammunition in an accurate factory rifle. The results were strengthened by the fact the trigger man didn't know what he was testing, so no preconceived notions.

Tag, good stuff

Hmm.. How does that work? I've heard that before but I fail to see how rubbing a paper clip along the side wall tells you what you need to know! Without a number the case wall feels "kinda" ok?

Have you tried looking in the cases with a bright flashlight? I've found I can see a shadow ring before I feel anything with a paper clip. Obviously this works better on some cases than others; I use a lot of mil-surp 308 brass and check all of them this way.

Thanks! I couldn't remember how the paper clip method worked. I got an RCBS Casemaster as soon as I started loading and can measure exactly what the case thickness is anywhere inside the case! I like to keep an eye on the area just ahead of the web for possible separation issues. Somehow the feel method never gave me a warm fuzzy feeling! lol JMHO

MD - very nice reasoning behind why I bought and am learning to use the data gained from a run-out gauge. I'm hoping the Sinclair helps connect some of the dots and reveals relationships between dies, brass and patterns of the holes on the paper. I do not own any custom rifles or dies. I have been frustrated in recent years with random flyers in my groups. I've bedded and re- bedded guns, changed scopes, did more case prep, about everything else - except evaluating each step in the load development process related to sizing brass. I'm hopeful the Sinclair and some study will help eliminate flyers and improve my session to session consistency. If not, I'm only out $100 and have added to the experience banks.

John would you say Remingtons and Savages have minimal chambers, I have many factory rifles I use for carry hunting and I don't check runout for these rifles and there all are 1/2" MOA or better rifles.o

Are you rich? If not, why haven't you cashed in your lotto tickets?

LOL. I have and yes I am

Possibly a stupid question given that I've been measuring runout - where do you guys measure runout on the bullet? I always thought it was measured on the ogive. I noticed in the Sinclair video they run the indicator close to the ogive in one shot and closer to the bullet tip on another. Which got me to looking on the interweb. Some guys measure it on the ogive, at least one source in a Wolffe pub says run it on the "parallel sides of the bullet" (VanDenburg), while others are forward of the ogive.

What say you guys?

On the ogive very near the body. That's where it's going to go into the lands.

I use whatever the instructions say that came with the tool. With the Hornady gauage it said to measure on the ogive, so I did. With the RCBS it said to measure about 0.1" in front of the case mouth, so I did.

What do the instructions for the Sinclair tool say to do?

bwinters,

I have a home made runout measurer. Since I got it from a friend I measure where I saw him measure; right behind the plastic tip.

What are the advantages of the other two places?

When do we get into making gold out of base metal?

The instructions and/or the video don't say. I called them and they said measure the loaded round on the neck which doesn't seem quite right. The wolffe article may have a good point with respect to measure on the "parallel side of the bullet". The thought is that any movement of the case longitudinally will cause the dial to slide along the long axis of the bullet giving inaccurate run-out measurements. I think that is more of a theoretic argument. If your case head is that warped, you have bigger issues than a couple thousands of run-out.

I'll keep doing it at the ogive. Measuring it out towards the tip would magnify any run-out due to the further distance along the axis of the bullet away from the crooked neck. It seems intuitive that the most important point is where the bullet contacts the lands/grooves, not the bullet point.