Neck turning or Concentricity gauge?

rayatphonix said:

Would you begin with a concentricity gauge or by neck turning your brass? I want to master one before I begin the other.

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Concentricity gauge. Measure twice, cut once.

Experimentation doesn't hurt but unless you're loading for a gun with tight tolerances, I doubt you'll gain much by neck turning. I have a neck turner and have turned the necks on probably 500 cases at least and can't say I've seen an improvement on paper.

I guess a concentricity gauge would help you detect imprecision in the reloading process; I have one and use it very little. Those times I've used it, the concentricity has been pretty good. Once again, I suspect you'd see the biggest advantage in a rifle with tight chamber tolerances unlike the usual hunting rifle.

What has helped my reloading process is an annealer I recently bought. Those Lake City cases I had turned the necks on had given dissapointing results until I annealed them.

I agree with Grmulkin:

Grumulkin said:

Experimentation doesn't hurt but unless you're loading for a gun with tight tolerances, I doubt you'll gain much by neck turning. I have a neck turner and have turned the necks on probably 500 cases at least and can't say I've seen an improvement on paper.

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The only rifle I ever turned necks for was a custom tight neck 6mm PPC. This was only because of the custom tight neck chamber and how my brass was made by fireforming Lapua 220 Russian. I would just focus on concetricity and not worry about neck turning.

Ron

Which rifle are you shooting and which cartridge? Are you shooting competition and if yes which discipline.

My vote goes for neck turning first because I can't run anything thicker than .012" with my undersize chamber neck. Even if the concentricity gauge said they were concentric they could still be dangerously thick so obviously I'd want to knock off the excess first. But I am not speaking from experience: premium brass is still available in my caliber so I've been able to avoid neck turning thus far.
My guess is that different case brands have different average neck wall thicknesses, and that the thinnest measurement is going to be what separates the wheat from the chaff in this regard. I wish you the best of luck in your endeavor - quality neck turning is a skill that is well worth learning IMO, and one that I'll need to master when I switch from my present .223 to the late great .222 rem mag.

Neither a concentricity gauge or neck turning is really necessary unless you're a bench rest shooter. Most of the daft gauges and other accessories the reloading companies are peddling are really just a way to separate you from your money. Different if you're fire forming or otherwise making other cartridges out of common cases, but for the average reloader you don't need it. You can load match grade ammo with a Lee Loader and a scale.

You won't know if any change you make helps reduce run out without a way to measure it.

If you have a way to measure runout you can find improvements that don't cost a penny. Like, for some dies, seating a bullet in steps while rotating the case in the shell holder. I have even measured improvements by simply chambering, then ejecting and measuring a loaded round.

That said others won't make a difference at all.

Consider these facts before you decide to turn your case necks to some uniform thickness:

* Benchrest group records through 300 yards comprising several 5- and 10-shot groups whose average extreme spread is the result posted. The extreme spread of the largest single group shot is typically half again the size of the average stated for record. Currently, for the existing aggregate records have half again that of their size are at about .3 MOA at 100 yards, .4 MOA at 200 yards and .5 MOA at 300 yards. All those thousands of other aggregates's extreme spread averages are larger. Virtually all are fired from uniform case neck wall thicknesses.

* Accuracy specs for all match bullets tested at 200 yards with 10-shot groups are inside .475 MOA for Hornady and .500 MOA for Sierra. Their 22 and 24 caliber ones are typically more accurate than the 33 caliber ones. Sierra’s standard at their California plant testing 22 and 30 caliber bullets at 100 yards was .25 MOA average with maximum at .375 MOA. Both use unprepped cases; no turned necks. Sierra uses Redding Full Bushing dies on cases they’re made for, Redding standard full length dies on the others. Hornady uses their brand of dies.

* Full length sizing dies with neck diameters .001" to .002" set to bump fired case shoulders back that much typically make case necks straightest on case shoulders. Expander so balls bend necks so they're not used. Bench rest folks pretty much gave up neck only fired case sizing some years ago. Their smallest groups stayed the same size but their largest ones got smaller using full length sizing dies with their necks honed out to some dimension.

* A fired case so sized in such a full length sizing die with neck wall thickness spread of .002" and straight on the case shoulder well aligned with the case body will have its bullet only .001" off center in the chamber leade/throat.

* Many tests have been conducted that proves bullets no more crooked from the case axis with a runout of 1% of bullet caliber (.0022" for 22 caliber bullets) shoot no more accurate than those perfectly straight with zero runout. Depending on the runout gauge design, cartridge reference points and where on the bullet the dial indicator is at, runout across them can have a .002" to .003" spread for a given cartridge.

* Forster will hone one of their full length sizing dies’ neck to the diameter you want for $12. Measure the neck of a loaded round then subtract .002", contact Forster and they’ll make it for you. Or get a Redding or RCBS full bushing die with bushing diameters you want. One make’s bushings will fit the other’s dies.

I use a Hornady concentricity gauge to check rollout on my loaded rounds. What I have found while using this tool is the brass makes a huge difference when searching for consistent accuracy. I have not been happy with the brass I've purchased for my Winchester 264 magnum.
Last November I took possession of my father's 1965 Win Mod 70. I had no load data from him or ammo. I bought a box of Super X and first thing I did was roll them on the concentricity gauge. Wow, .022 of crooked mess! So I did an experiment. Kept 5 at factory loaded mess, 5 I straightened with the gauge. The other 10 I straightened the round then pulled the bullets, dumped the powder and averaged the charge and resized the brass. I noticed when you straighten the round with the gauge, it will reduce neck tension if you have to really push on it to get where you want it. So the next 10 rounds will focus on neck tension. I loaded up 5, same powder charge, brass as good as my FL resized could do, and seated the bullets to the same depth. The last 5, I measured the brass at 3 points, mid body, shoulder and neck. I seated a bullet deep (no powder or primer) and eventually straighten the brass at these 3 points. The bullet may not wobble at the ogive on some rounds but I noticed the body of the brass was. So, the last 5 were straight from bullet tip to half way up the body. I pulled the bullet, resized the brass and loaded. There was a noticeable difference in accuracy between all of the groups. One thing I learned was when I use the gauge to straighten a round, I push on the neck just above the shoulder neck junction, or base of the neck. This has far less affect on neck tension. If the brass is really out of wack, I also push at the shoulder, being careful not to dent the brass, Just a few thousandths here then finish at the base of the neck.
So to recap, a straight round (consistent powder charge, seating depth) shoots pretty good unless the neck tension is all over the place. Now for neck tension, next post

Thinking new brass would solve all or most of my accuracy problems, I bought 50 pieces of Nosler brass. Eventually I bought a neck thickness gauge from Hornady that uses the base from the concentricity gauge. Neck thickness was all over the place on all 70 pieces of brass I now have. The necks are pretty thick and takes a lot more pressure to seat a bullet than the brass for my other rifles. It also has crazy velocity swings when shooting ladder tests as an example. I'd never experienced this much neck tension before. After measuring with the neck thickness gauge I set my neck trimmer at .015 gap and turned 15 pieces to test. At this setting the necks have a .0015 variance and the velocity was a lot more consistent and accuracy also improved. Bullet seating pressure is less than before and pretty even now.
A loaded round measures .2945 at the neck. A fired round measures .301. So this is not a tight neck (hunting rifle) but turning the necks sure evened out neck tension. In my case, one tool or the other would not fix the problems I faced. It took all three tools, Using the neck gauge to help find a thickness to use across the whole lot of brass. Guessing at the neck thickness would not have been as good.

I bought a chronometer several years ago. It taught me I wasnt as good a reloader as I thought I was.

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What chronograph and why? You can "bench race" numbers all day long but at the end of the day the diameter of the group is the number that is important, at least sometimes.

But no it really doesn't change anything, if you are reaming or turning in the name of reducing runout, how would you know without a way to measure changes, if you are doing any good?

You might be doing extra work and spending money and think it's doing you some good but if you have no way of measuring the difference you won't know.

Not unlike people blowing money on loud mufflers and thinking they now have a tuned race engine but never do anything to quantitatively test the difference, to see if it did any good at all.

In my case, inconsistent neck thickness problems were solved by turning the necks. But I could tell there was a problem just from seating bullets. Some were tough to seat, others were really tough. I haven't had time to run too many accuracy tests on this rifle. On another rifle, I left no stone unturned. Full length bushing die resized brass set to bump shoulder back .002, necks turned for .0025 clearance, sorted bullets, brass, upgraded stock and bedded action, barrel floated to .040, annealed necks, etc. It went from constant .6x groups to .2 - .3's in a 27 year old gun. I think upgrading and bedding the stock helped the most. But I did most of the brass prep before changing stocks. I've seen good results from annealing necks too.

Bart B. said:

Forster will hone one of their full length sizing dies’ neck to the diameter you want for $12...

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...another good tip thx Bart B.

Regarding a given load's ability to shoot bullets with a small spread in muzzle velocity tested with a rifle.....

...hand held against one's shoulder resting arms on a bench top = big ES and SD, lowest average fps.

...hand held slung up in prone with bag under fore end and stock toe = medium ES and SD, medium average fps.

...barreled action fixed in place so it won't recoil = lowest ES and SD, highest average fps.

Several people shooting the same rifle and ammo hand held from a bench can have average fps several dozen apart. I've seen near 100 fps spread in averages.

No question that technique is major, major factor in maintaining consistency but Bart B. I'm still able to sense when my rifle has jumped as a result of fouling. Obviously I'm hard pressed to explain this but there's no question in my mind that rifle twist and jump at the bench is exacerbated by hard fouling.

Then your situation is unique to your system. Especially when it isn't observed shooting in any other position. If it does happen in offhand, you should be able to sense it. Theories require facts, spitballer.

Nobody else has ever claimed it happens.

I have never experienced anything I could say was attributed to fouling.

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Shoot enough 38's and 357's don't like to chamber/eject as smoothly.

Walkalong said:

Does this happen at random, or...

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It depends on the load. If I'm only slightly overcharged I can usually get off a half dozen rounds before flyers. This morning I got lucky and ripped off 20 quick rounds without any fouling trouble, but usually I'll get flyers after a few shots, and the movement of the rifle at the bench is definitely exaggerated when they occur.

With any hotter loads, velocity, recoil force and direction and your body aiming the rifle will have greater exaggerated movement in all directions that when maximized, will cause those fliers. Has nothing to do with bore condition.

This is why small bore rim fire target rifles produce smaller groups at 100 yards than high power rifles twice as accurate (1/3 MOA vs. the 22's 2/3 MOA) when both are shot from prone. Even though the 22 rim fire bullets are in the barrel twice as long as center fire bullets so the rifle has to be held still as possible twice as long after the round fires in the chamber.