Home Forums Hunting & Shooting Ask The Gunwriters The Bullet or the Recipe Pushing It?

I agree. I started chasing concentricity in my loads several years ago and never realized gains in accuracy.

Good, consistent neck tension yields better results IMO.

Again, would like to hear about your tests.

I've described just some of mine, but have many other examples.

Would agree that consistent neck tension is part of it, partly because that usually implies consistent neck thickness and sizing--which usually results in more consistent bullet alignment.

Not trying to start an argument, but in my limited testing the gains in accuracy I've seen have been due to consistent neck tension.

I bought a Remington 308 5R a few years ago and bought 200 rounds of Lapua 167 gr match ammo with it to have the great brass for reloading. The match ammo was 1/2 MOA or better, fantastic stuff. 10 shot groups with no flyers into a ragged hole without really trying. So I started testing loads with this brass and was getting my best results with Hornady 168 gr AMAX bullets but not quite a good as the Lapua. My reloads were sized with a Forster FL sizing die and my bullet runout was consistently.0015 -.003 seated with a Forster Micrometers die.

I decided to measure bullet runout on some of the Lapua match ammo and to my surprise it was .003 to .006. I decided to buy a Redding bushing neck sizer die to see if results improved. I used a .336 bushing and sized about 2/3 of the neck. Concentricity also improved to consistently under .0015 bullet runout.

The results were improved accuracy without flyers for this gun. I've bought a few more of Reddings FL bushing dies for some of my other guns and have also seen some improvement in the little amount of shooting I've had time for in the last couple of years.

Certainly not a scientific analysis, but my limited results show that sizing brass for consistent neck tension will yield better accuracy. Yes, concentricity also improves when sizing with bushing dies set up properly, but I was already getting concentricity of .004 or less using standard FL sizing dies.

I would never try to compare my shooting experience with yours, and one reason I tried the bushing die was from watching your reloading video. It's just my opinion from my comparatively limited experience that good consistent neck tension will improve accuracy, and better concentricity is a byproduct of better neck tension, not the primary cause for improved accuracy.

Hmm.

Here's what you found with your one "experiment":

"I decided to measure bullet runout on some of the Lapua match ammo and to my surprise it was .003 to .006. I decided to buy a Redding bushing neck sizer die to see if results improved. I used a .336 bushing and sized about 2/3 of the neck. Concentricity also improved to consistently under .0015 bullet runout.

"The results were improved accuracy without flyers for this gun. I've bought a few more of Reddings FL bushing dies for some of my other guns and have also seen some improvement in the little amount of shooting I've had time for in the last couple of years."

Am puzzled about how you came to the conclusion that the improvement in accuracy was due to more consistent neck-tension in your handloads rather than bullet run-out--especially when "concentricity also improved to consistently under .0015"--especially during "the little amount of shooting I've had time for in the last couple of years."

Would like to hear your own tests, instead of what you Googled up....[/quote]

John, I shoot 1000’s of rounds some years (not this year) and have been handloading pretty seriously for 30 years. I used to chaise concentricity like it was the holy grail of accuracy. Why wouldn’t I? It’s all anyone could talk about at times. If you had flyers it must be crooked ammo. Right?

I bought die’s after die’s trying to eliminate one or two thou runout, had custom die’s made, went exclusively to a Forster Co-Axe, had bushings made, honed necks etc. This messing around with the necks of die’s was pretty much the catalyst that made me think twice about runout.

All this time I was thinking about annealing as well. For 20 years I have annealed brass. With candles, propane, using fingers, tempilaq, salt bath, and finally now an AMP. honestly if you aren’t using an AMP all you are doing is preventing split necks (now that ought to create angst).

Here is what I think. The idea that brass is the least important part of the handloaders recipe is nonsense. Why? Because the single biggest factor I have found in group consistency (not necessarily group size) is neck tension. To get consistent neck tension you need good brass, you need good dies and you need consistent annealing. Or no annealing at all.

In all of this, I also started to see runout not rearing it’s ugly head like I thought it should. Over the last couple of years I have tested that theory and have found loads with even 0.010 of runout landed right where they were supposed to. If you are getting more runout than that I’d suggest a mechanical overhaul.

I also think that powder charge matters (I use a lab grade scale), seating depth is huge (though seating depth close to, or into the lands is far from necessary or even preferred).

I’m no expert, but I’m not exactly green either. I’m developing loads in a hunting rifle context. I have my own private 1000 yard range and use it. If you are struggling with your groups I’d certainly not blame runout right away. It may not be the culprit at all.

I've shot a couple thousand rounds with the 308 rifle I mentioned. Accuracy was better after switching to the bushing dies even though my concentricity was already within the .003 limits you have mentioned. And the very accurate factory ammo was less concentric than these limits.

Do you think improving concentricity by .0015 is the reason for better accuracy?

Or could it be something else?

It’s something else.

I'm not a benchrest shooter but have been reloading for 40+ years. On neck tension, I bought a Forster neck tuner, ran batches of cases though the process, by hand I was surprised how much neck thickness varied within an identical batch of cases. I still beleive neck tension, as proxied by neck turning, and concentric ammo play well together and result in the most accurate ammo. At least in my mind based on what I've tried over the past 10 years or so. I've yet to try benchrest dies mainly because MOA or better works for me. I really don't care if my hunting rifles shoot 0.5 MOA or 1 MOA. I dont shoot beyond 400 yards so it's pointless for me to add more frustration into the hunting equation. I spend my time training and finding elk and deer rather than chasing another 0.25 MOA.

patherfinder76 and AU338MAG,

Where did I write that bullet concentricity is THE answer to accuracy?

There are a bunch of factors that go into rifle accuracy, and some of them will vary a little depending on the type of shooting--as I mentioned earlier in this thread. But the reason I often emphasize bullet concentricity is that while I write for a wide variety of readers, the most common is the average hunter who handloads, who's often looking for something as basic as CONSISTENT 1-inch accuracy at 100 yards, usually when firing 3-shot groups.

One of the first things I suggest is measuring bullet run-out. Why? Because if it's excessive, it's a definite symptom that something's wrong with their set-up and/or technique. There may be other problems (and usually are) but until they can turn out ammo with consistent bullet concentricity in the .003" range, then they're wasting their time on other stuff--such as weighing every powder charge to .1 grain.

The causes vary, but perhaps the most common is uneven case-neck thickness, which of course results in inconsistent neck tension--which is of course a major factor, especially with a lot of common factory brass.

But bullet concentricity can also be caused by several other problems, such as as case necks being pulled out of line by the expander ball--and there several possible problems there as well. Another common cause is how well the bullet matches up with the seating stem. Annealing is of course another possibility.
All of this is why I constantly experiment with various rifles, cartridges, components, scopes, shooting techniques etc.

It's also why I bought my benchrest rifle. I have little interest in shooting in matches (though have won or placed in some informal ones over the years), but wanted own a rifle accurate enough to be able to isolate various factors in accuracy--though noted earlier, these can vary somewhat with the quality of the rifle, and even if it's of high quality, whether it's designed to be basic hunting rifle other a benchrest rifle. It doesn't make any noticeable difference in many hunting rifles to go through ALL the steps of making benchrest ammo, because in all likelihood the case are going to be full-length sized for sure and easy chambering under hunting conditions, which often involve complications such as dust, moisture, etc. So there's going to be a little variation in the way the bullet enters the rifling, even if there's zero detectable bullet run-out or very consistent neck tension. Which is why .003" of run-out generally gets all the accuracy possible out of "standard" hunting ammo.

But if we're discussing the finest accuracy possible in a short-range benchrest rifle then the game changes. There can be detectable differences in accuracy due to neck tension, bullet seating depth, and even a slight amount of bullet run-out. Quite often such rifles respond best to the bullet being jammed into the rifling--and accuracy can even vary on how "hard" the bullet's jammed.

How much neck tension is required is another interesting question, one of the reasons I've experimented considerably with annealing, including methods from candle flames to an AMP. Have also experimented with whether annealing brass after every firing makes a difference: One of the experiments I ran with my bench rifle was NOT annealing the cases for up to four firings--but making sure all the cases used to shoot test-groups had been fired the same number of times since the last annealing. I could not find any significant difference in average groups sizes, whether the cases had just been or annealed, or all fired 4 times--but could see a difference if cases fired a varying number of times were used in shooting groups And as mentioned in my earlier post, this rifle is capable of consistent 5-shot groups of well under .2 inch.

But even the simplest annealing method can result in vast improvement in accuracy. One of my several "accuracy gunsmith" friends called me 2-3 years ago, because a 7mm Remington Magnum he'd just built would not group three shots under two inches at 100 yards, and some groups were even bigger. Now, he's not an accuracy handloader. I believe he may check bullet concentricity by rolling rounds across a flat surface to see if there's any apparent bullet-tip wobble (if there isn't, concentricity is generally no more than .005"), but he doesn't uniform brass, or often even fire it more than once. Generally he loads new brass, and gets 3-shot groups well under an inch on his indoor range from the rifle's he builds.

We ran through a bunch of possibilities, and finally I asked if he'd tried annealing the brass. Turned out he'd never annealed brass in his life. But some factory brass can miss getting annealed, or be annealed erratically. Of course, he didn't want to buy any sort of even moderately expensive annealing equipment, so I described the candle method, and told him it could also be used with a propane torch. He called me back a few hours later to say the rifle was now shooting half-inch groups.

Also experimented with a Juenke machine for a couple of years, to see how much difference bullet "balance" made in accuracy. Of course, it turned out to make considerable difference, and not just in match bullets but hunting bullets. Turned out a batch of 165-grain, .30-caliber Nosler Partitions I'd been using for several years in various rifles were almost as perfectly balanced as typical Bergers--and the Partition had grouped extremely well in rifles from a couple of .308 Winchesters to various .300 magnums.

But once again, my point about bullet concentricity is NOT that it's the ultimate answer to rifle accuracy, but that it's something to start with when a typical hunting handloader wants to build more accurate handloads, because it leads to finding where the problems lie. Neck tension is one, of course, but there are several potential causes for problems there--which often leads those handloaders into other techniques, from brass sorting to neck-turning to annealing.

I have always prided myself on being able to fix 90% of the accuracy issues at the loading bench.But currently I have a .243 that doesn't 'like' 95 gr. NBTs Odd cause Ive always had easy luck getting NBTs to shoot in anything.Anyway I tried everything you mentioned plus seating depths....nada.

Could it be the crown configuration, even if it's even, just doesn't get along with the different little boat tail Nosler uses?

It has seemed in some of your writings, posts and videos that achieving very concentric ammo was the key to more accurate ammo, but maybe I misunderstood what you have been saying.

I agree that non concentric ammo is a symptom of something else being wrong with the process. It could be a bad sizing die, seating stems not matching the bullet, bad brass or bad loading technique. Inconsistent brass is the worst, which is why I try to buy as good of quality brass as is available for a cartridge, but sometimes I got stuck with using poor quality brass for a cartridge like a 7x57. Yes, Nosler makes brass for this cartridge but it is outrageous in price so I'm using Remington and Winchester brass, which is the worst brass I've ever measured. Variance of .003 in neck thickness and bullet runout of .005 -.010. I'm getting acceptable accuracy in my old Ruger M77 but it's been damn near impossible to get good accuracy in my brother's M70 FW. 140 partitions group into about 4", but I've been able to get 139 gr Hornady SP to 1-1/2 inch groups.

I will never be confused for a competition shooter, but I've been rolling my own ammo for over 35 years. I load for hunting rifles, not benchrest guns, but I try to use loading technique used by competition shooters. Many of these shooters are obsessed with preparing brass for consistent bullet release, and are not concerned with bullet runout. Consistent seating pressure is what they're trying to achieve.

Maybe it's another rabbit hole to go down, but that's what rifle looneys do.

Odd...

I've used different bullets to check accuracy over the years. In 6mm I liked the
Speer 90 Spitzer, or the Sierra 85 bthp.

Last few years I just grab some Nosler BTs in either 70 or 95 gr configuration.

If a rifle won't shoot them???

AU338MAG,

Twenty years ago typical Remington and Winchester brass was pretty good. I used to sort it for even neck thickness, no more than .001" from one side of the neck to the other, and end up only rejecting 10-15% of the cases. But that changed over the next decade or so, to the point where sometimes I only found 15% of the cases met my standards--so I started using better brass, such as Lapua.

But in recent years quite a few other good brands have appeared--and around 4-5 years ago I also discovered Hornady brass had become much better dimensionally. In fact, I bought some of their .275 Rigby brass, partly to test one of the new Rigby rifles for an article. Didn't buy that rifle (even with the writer's discount it would have been more than I wanted to pay!), but a year or so later did trade into one of Ruger's "African" Hawkeyes in .275, which shot very well using the Hornady brass, as around .7 inch with 140 Partitions. Have also had recent luck with Hornady 7mm Remington Magnum brass, which turned out to basically match quality--and while it cost more than Remington or Winchester, it wasn't nearly as much as Lapua or Nosler.

There are some other good brands that aren't an arm and a leg, which I mentioned in an article for HANDLOADER a couple years ago, and republished in somewhat different form as a chapter in GUN GACK III.

I have bought some of the 275 Rigby brass but have not had a chance to try it out. I changed jobs and moved to another city and my shooting time has been severely limited over the last couple of years. Winchester brass used to be good years ago but the last couple of batches I've bought have not been good. 300 WM and especially the 7x57 brass has been the worst I've ever measured. No technique can make bad brass good.

Nosier brass has been very good in my experience. I bought Nosler 257 Roberts brass about 10 years ago when I bought a Bob and is haven't even had to trim it through 5 or 6 loads. Only compliant I've had with their brass is the primer pockets usually need a good uniforming or I can't seat the primers properly.

I don't want to get into an argument with you about the concentricity issue. I certainly have less experience than you, but after spending years sorting ammo by bullet runout, I never saw any significant difference in accuracy between low run out and those with more than.003 runout. It's just an opinion based on my experience. I don't expect benchrest accuracy from my hunting rifles, but I do expect and can achieve MOA or better from all of my rifles with one or two exceptions. My 35 Whelan AI is a 1-1/2 MOA gun, but that's not bad and it's certainly not a long range gun with 250 gr RN bullets. Guns that I will use for long range hunting I want to get 1/2 MOA accuracy and can with a handful of guns. When I refer to long range I'm thinking out to 600 yards, which is a self imposed limit which I will only try if conditions are right.

[quote=Mule Deer]
But in recent years quite a few other good brands have appeared--and around 4-5 years ago I also discovered Hornady brass had become much better dimensionally. In fact, I bought some of their .275 Rigby brass, a year or so later did trade into one of Ruger's "African" Hawkeyes in .275, which shot very well using the Hornady brass, as around .7 inch with 140 Partitions. [quote=Mule Deer]


I'm shooting the Hornady .275 Rigby brass in my Ruger African, with 150 gr NBTs, it is superbly accurate.

As noted in one of my earlier posts I HAVE seen considerable difference in accuracy depending on bullet run-out--even in factory ammo, as was the case with the custom 7x57 and Hornady ammo I noted. Have also seen similar results with other brands of factory ammo.

Might also mention that several of my reference books on accurate rifles and ammo do mention bullet alignment, especially two benchrest books, Extreme Rifle Accuracy by Mike Ratigan, and The Ultimate in Rifle Accuracy, by Glenn Newick. David Tubb's book The Rifle Shooter, also mentions it in a different way, because he often prefers to do the final seating of the bullet when chambering the rounds, so the bullet is centered and aligned by the rear of the lands. I also recall reading somewhere--probably in one of my other books such as The Benchrest Primer, a collection of articles from Precision Shooting magazine--about a test made with the "high" side of slightly misaligned bullets marked, which demonstrated that if the rounds were all inserted in the chamber with mark in the same attutude, whether up, down or sideways, that they grouped smaller. Another test was to insert the rounds with the mark turned to different points. I seem to recall it was written by Creighton Audette, a noted competitive shooter, gunsmith and writer, who was responsible for a number of innovations, but could be wrong.

But I also mention bullet alignment frequently partly because so many handloaders don't have any idea how much it can affect accuracy, or that it even exists. This especially applies to new handloaders--and a BUNCH have started recently. Plus, one of the realities of magazine writing is some turnover of readers: One BIG magazine I was a staff writer for in the 1990s figured they had an almost complete turnover of subscribers about every three years. That's not nearly as true of gun magazines, but still a factor. So some stuff needs to be repeated periodically--especially since so many new handloaders believe weighing charges to .1 grain will make a huge difference in hunting-rifle ammo, when other factors are far more important.

I would imagine that one reason some competitive shooters don't mention bullet alignment is they worked any problems out years ago, and use loading equipment that minimizes run-out. As a result they don't worry about it. I certainly don't when loading my uniformed brass for the 6mm PPC bench rifle, because I know that brass in my dies will result in alignment well under .001".

But also, as previously mentioned, I know that when hunting handloaders having trouble getting the accuracy they desire, that if they become aware of bullet alignment it becomes a "gateway drug" to improving their brass, tools and other techniques to eliminate potential problems.

Laughing. Be suspicious of it all you like. Test it yourself.[/quote]

You think I haven't? Just a few days ago, I tested my 6PPC rounds with less than .0005 runout, against the loads that came with the rifle that had the necks running out .0025, and the bullet .005. Same bullets and powder all from the same boxes. Mine went .147, the others went .656. Shot over windflags as well. All I know is, when someone tells me concentricity doesn't matter, they don't have any idea WTF they are talking about, and anything they are bloviating about isn't worth listening to.

AU338MAG,

I was wrong about the experiments of bullet concentricity being done by Creighton Audette--though he may have done something similar. I found one such test in the book RIFLE ACCURACY FACTS, by Harold R. Vaughan--an actual rocket scientist, who started out studying the trajectory of artillery rounds, but moved on to rockets, and eventually headed the Aeroballistics Division of Sandia National Laboratories (a division of the National Nuclear Security Administration) in New Mexico.

But he was also a rifle loony, who performed a number of scientifically based tests and modifications on one of his hunting rifles, in order to isolate and solve various aspects of accuracy. He used a lot of high-tech tools and measurement devices not available to most handloaders, and among his findings he proved that seating bullets even a little "crooked" resulted in definite (and pretty predictable) deflection during flight, due to powder gas escaping slightly sooner on one side of the bore at the muzzle than the other.

The book was published in 1998 by Precision Shooting, which is where I bought my new copy for something like $30. Used copies run for $200-$400, depending on condition, but a PDF scan can also be found on the Internet. The relevant information begins on page 133, under the heading Canted Bullet Test.

John:

Although quite a bit slower, have you found that Wilson-type seating dies result in less concentricity, assuming case necks are of uniform thickness and correctly sized?