Home Forums Hunting & Shooting Ask The Gunwriters Run-Out: what is allowable given different circumstances?

Hadn’t thought about that aspect. I’ll have to give that a try.
MD, your technique of depriming separately and moving the expander ball up in order to expand the neck while it’s still partly contained by the neck portion of the die has helped with several resizing dies. It works.

I would like to apply for a federal grant to study this.

I bought a second-hand, custom rifle built by the late Gary Stiles. It is chambered in 257 Roberts. I took it to the range with some of my hand loads. It was shooting 2.5” groups at 100 yards with the loads I tried. I was at a loss. I have loaded for about 10 years. But kept things simple. Then I remembered something I had read by Mr. Barsness on this forum about run out. I rolled a round across my bench and the wobble was pronounced. Every loaded round did the same thing. I bought a set of RCBS dies to replace the Lee dies and also bought a Hornady concentricity tool. Problem solved and I’m able to get groups <1” out of the Stiles rifle. I’m a believer in the importance of straight ammo.

A little 'straight ammo' incident:

My local police department had three Remington 700 PSS 308's that were contracted to my good pal, the late Stan Ware (SGR Custom Rifles), for rebarreling and action work due to a pretty significant accuracy fall off. Two of the SWAT team members assigned to these rifles were guys that Stan and I shot registered IBS and NBRSA Benchrest tournaments with, so they were very capable shooters. The department had used factory Federal 308 Gold Medal Match ammo (Sierra 168 Match King) for a long time and it had given 3 shot groups of right around 1" @ 100 yds for all three rifles. More importantly, the first shot from either a clean bore or a 'fouled' bore went right were it was supposed to go...an important 'must' if the rifle(s) were ever fired at a human, given the subsequent litigation and investigation that will follow.

Anyhow, the rifles were to come over one at a time for the rework along with several boxes of the Federal ammo for test firing after the rebarreling. Prior to pulling the barrel on the first one, Stan test fired it at his home range for documentation. It struggled to shoot under 2" at 100 yds. I rolled some of the supplied FGMM ammo across the workbench and the bullets wobbled around like a Saturday night drunk. We pulled bullets, dumped the powder out of each case seperately, sized the cases in a Redding f.l. die, dumped the powder back in each case, reseated the bullets with a Wilson seater and an arbor press and went to the range again where rifle now shot 5/8" 3 shot groups.

We never measured the run out on the 'before' ammo but it was likely close to .012-.015 out of the box. The 'after' ammo was .0015-.002 as measured on my home crafted concentricity gauge.

The department wisely decided to rebarrel all three guns anyway. The excessive run out FGMM ammo was returned (I think there was about 4,000 rounds remaining of that lot number) and the rebarreled rifles (with a chamber designed to better fit the dimensions of the FGMM ammo) all were capable of 1/2" FIVE shot groups with the replacement lot of FGMM ammo that had T.I.R. about .003.

M.D.'s comment about rolling ammo is spot on. If you can see the bullet tip move when you roll it across a flat surface, it's > .005.

Just a note about concentricity checkers for those considering purchasing one. I made several designs before settling on the one I have now. Anything with a base 'stop' (a pin, etc) can transfer base condition issues that may show up on the dial indicator as stuff that isn't really there. A lot of that depends on the internals of the dial indicator, as well.

My 2 cents this morning over a second cup of Sulawesi.

Good shootin' -Al

Yes, maybe on the base stop but what is FAR worse is a gauge like the Hornady concentricity gauge that holds the case face in a cone on one end and the bullet tip at the other. It showed ammo to be straight and when the same ammo was rolled in the Sinclair gauge, it showed to be considerably off AND also was noticeably visible. Any irregularity on the case face can show up on the dial indicator.
The Hornady gauge is better than nothing but it is not nearly as good as the Sinclair IMO.

Noted, SoTex. I’m always interested in upgrading equipment. 🙂

I never paid attention to case necks or cartridge runout. But after my short time of being a 24hour addict and reading how crooked ammo can effect accuracy I decided 6 weeks ago to buy a Redding Slant. Boy did I get an awakening.
I Always thought that all ammo was straight. I’ve since bought Forester sizing and seater dies for four of my bottle necked rifle calibers. And all so made my own cartridge straightener out of a piece of angled aluminum.
I haven’t had a chance to get any shooting done because of the weather, but let’s just say I’m ready to go.
Any of my loaded rounds that were way out of wack I pulled and reloaded using the Forester dies. It worked some of the times and some times it didn’t. I’m thinking it’s the brass. A lot of the brass I’m using is Winchester and Hornady. And a lot of it is new unfired. I want to get at least one firing on them before I make any final decisions. But I have enough brass that I can find the good ones to use.
From what I’ve read and if I had to do it over again I would have went with Lapua brass and the Forester dies from the beginning.
Now with all that said I’m by no means a sniper, long range hunter or shooter. But I want straight ammo.
My old dies (RCBS & Hornady) would have been good enough for what I do, but it’s a mental thing for me.
I figure I already had rifles that would out shoot me. So now I’ll have the ammo too.

Heavyload,

I used to use a bunch of "standard" factory brass from Remington and Winchester when I first got into the entire straight-ammo/accuracy thing about 30 years ago. The first thing I'd do, however, was run the necks of new cases over an expander ball, then measure neck thickness with the Casemaster gauge RCBS sent me for a a review, sorting out any cases with necks that varied more than .001 in thickness.

At the time I only rejected about 10-15%, which was a lot cheaper than buying more expensive brass. Federal was also offering their Gold Medal brass then, and it had an even lower rejection rate. But about a decade later Federal quit offering Gold Medal cases, and I noticed the rejection rate of Remington and Winchester bulk brass had gone up considerably, often 80-90%.

There have been exceptions since then, such as the bag of 100 Winchester .222 Remington cases purchased at a local store a few years ago, which were excellent. In the past few years I've also found that Hornady brass has generally improved a LOT, so use a lot more. Have also had great But am also not hesitant to buy Lapua or Peterson or other brands of high-quality brass, especially for a big game rifle where 50-100 will last a lifetime. Such consistent brass makes an immediate difference, especially dies like Forster Benchrest.

Heavy,

I'll revisit a point Al mentioned in an earlier post, namely that sizing dies may well size down the case necks more than necessary. Aside from cold working the metal, this dimensional issue can cause runout even if everything about the die is straight and the brass is uniform.

The Forster sizing dies have the rubber washer already so that’s a plus. I don’t think I’m going to be having my dies custom machined though.
I do have a question, let’s say the cartridge has .005/.006 runout (more then likely from bad brass) and you use the cartridge straightener and get it down to .002. Will that cartridge be just as good as a cartridge that has .002 runout from the beginning without straightening? And will that case always need straightened out?
And if a case neck varies more then .001 let’s say .002 or .003 will the runout of a loaded cartridge probably be double that? .004/.006 even with decent dies.

BTB, I didn’t mean to slam you or your Hornady gauge, but was just trying to point my experiences with it. On my Hornady concentricity gauge, I can move the spring loaded end that holds the bullet tip by .004” (rolling a loaded case in it) and that is just with my finger tip.
I have learned things the hard way myself. That is how I ended up with the Sinclair gauge. (Laugh)

Excellent thread! Exceeding all of my expectations. Thank you all for asking and answering such great questions. Indeed I’m
learning a ton.