Home Forums Reloading Big Game Rifles Effects of runout on precision

Interesting test from YouTube earlier today. His results indeed do reflect what I’ve experienced with runout. He theorizes that how tight free-bore is will be more tolerant to bullet misalignment. This theory would explain why it seems to get newer cartridges to shoot very good compared to older cartridges that have been around for longer.

I know that my loading took a precision turn after purchasing J.B.'s dvd, "Precision Reloading". It prompted me to purchase premium dies & stop buying the cheap run of the mill junk. Surely improved my accuracy by a great measure.

Learn how to set up your "cheap run of the mill" die sets and you can improve your run out tremendously. Those that don't get that, can try to use more expensive die sets and still have issues.

I think it was J.B. a couple decades ago that said regular dies could be used with great results with minimal run-out if the necks were expanded with a seperate step pushing the neck up over the expander rather than pulling down over. My memory is a little foggy that far back but it had to do with the shell holder only being "square" for the pushing action of the ram and not pulling.

I can attest to that working though, exponentially better. I've since progressed to Redding bushing dies and Sinclair expander stems for my precision stuff. Which virtually eliminates all run-out on annealed cases with consistent neck wall thickness. I like that system because the bushing die minimally works the brass, and the expander stems precisely set my neck tension AND sets a more concentric neck on the up stroke.

THIS and the video mirrors my experience. Runout doesn't make as much difference as most people think.

The video limited TIR to .006", which really isn't a lot.

And, not all chambers, like literally most of them, have a tight free bore.

Not to mention an example of only one rifle, one bullet, one load, Yada, Yada, Yada.

Kiss,find pressure and rock on. Newest rifle and this morning was first time I shot it,with but (1) charge weight,(1) bullet and (1) COAL. Forming cases too boot and magfed. Boresighted at 50yds,shot once and gunned a Hasty 100yd Trio. Hint.











Not much to it(ever). Hint................

A general comment:

I always love it when somebody mentions ONE article/example/etc. of what I've mentioned over the years about this subject.

The video did use one example of runout and grouping, because it videos have to be pretty short and pretty basic. But it proved the major point: That checking ammo (whether handloads or factory) for run-out does indeed result in smaller groups.

One of the examples I've mentioned here and there is testing some Hornady Light Magnum factory ammo in a custom 7x57. Bought several boxes of it at a store around 20 years ago, which featured the 139-grain boattail Spire Point Interlock. I sorted it into three batches, one with no more than .003 runout, one with .004 to .005, and one over .005--which as I recall went up to .007. The .003 batch averaged around half a inch for 3-shot groups at 100 yards, the .004-005 around an inch, and the over .005 about 1.5 inches.

How much run-out "matters" depends on the rifle, load and its intended use.
In my 6mm PPC benchrest rifle anything more than .001" results in larger groups. In most factory varmint rifles over .003" results in larger groups. In most factory big game rifles .005" or maybe .006" will do as well as loads with less runout.

I recently did an experiment with an old 1990s Remington VS chambered in .308 Winchester.

I took three boxes of Federal Good metal match and sorted them from 0.000-0.003”, 0.0035-0.006”, and +0.0065”+ and placed them back in the boxes. I wrote on the inside of the box which group it was.

Then I threw the boxes in the shooting bag and headed to the range. I wrote with a sharpie 1-3, and did targets the same. I didn’t look at which box was which until I got home. I shot three groups with each one and averaged them. I found no significant difference in group size between any of the three.

Had you offset OEM seating,then simply Smooched,you would have. Hint.

90's VSSF here. Hacksawed The Chop,made some sparks and whirled a deburring tool. Hint.








Keep reading and watching movies. Hint.

Fhuqking LAUGHING!...............

If a few thousandths runout is significant in your rifle, then you probably either spent a lot of money for it, or got very, very lucky. If coaxial alignment of bullet and bore is the ultimate aim, a lot of other factors need to be controlled.

I sorted Lake City M118 Match ammo and had someone else do the shooting. I didn't tell him what the test was. The runout did show, with the bad ones shooting groups looking like the numbers around the face of a clock.

My conclusion to when I tested it.
How do you even know if your chamber is even concentric
to the bore? I would worry more about that and freebore dia and the smith who put it together.
Test it yourself instead of listening to the internet.
I know BR guys who have tested it and say within reason about .006 TIR it makes no difference on paper.
I haven't measured mine in years.
I surely wouldn't do a test with factory " match" ammo ive seen it be 100fps E.S and couldn't do any better than 2" at 100

Yea, and being the last step in the process, have you ever watched how some people seat bullet?
I ,in particular like watching guys set the bullet on top of a loaded case, then jam the bullet into the case as it`s seated.

IME the last thing you want to "F" up is seating. For me the process I use works fine. I`ve never checked run out..and I use RCBS, Hornady, and I even have an old set of Herters I use now and then.

Think about what you`re doing when you set a bullet.

A Comp Seater was beautifully pictured,for you slowest of folks. Hint.

Do tell how you Fhuqktards do it and try to keep a straight face with your "process". HINT.



Fhuqking LAUGHING!.................

Please explain your seating method.

Inline seating dies made from my reamers HINT....

Imitation is THE most Sincere form of Flattery. Hint.

Bless your heart.

Hint.

Fhuqking LAUGHING!.................

Sure...necks are anealed, I do this after every firing, air cooled. I find anealing helps with consistant bullet steat depth. I also find that before sizeing and pulling the case over the expander ball, I use a very LIGHT lube of Imperial wax, applied with a cotton swab,to lube inside of the neck..then the outside of the case. Over the years, I`ve gotten a "feel" for this. Thoses who have it know. what I`m endvering to do is keep the case concentrict. I wipe the outside of the case clean, then into the trimmer. Mostly because of the pressures I run, and how I have my die set up, this only requires a touch up. After sizing, and this is step is I think, important, I put a very good champher on the inside ot the neck, then outside. I then take OOO steelwool and polish the champher, getting it smooth for the seating process. Prime and fill. The case goes into the press, I sellect a bullet at of 20, that have already been chosen for consistant BTO, place on the neck and guided into the seat die with my fingers. I then run the case and bullet up to meet the seat stem. When I contact the stem, I stop, and GENTLY, using my fingers, lift the press handle just a little and drop it on the bullet, GENTLY, several times. If you can picture this, what I`m doing is aligning bullet, die stem and case. Should you do this a bit ,you can feel the process. I do Not start the seating process until I`ve done this. Start the bullet down the case neck about half way, turn case 1/2 turn and complete the seat. Check bullet seat depth.

I`ve never checked my run out.

This sounds very time consuming but is really not. Just part of my process, and goes quickly.

YMMV
,

I'm laughing sooooooooo fhuqking HARD,I'm fhuqking CRYING! Hint.

Bless your heart for trying.

Hint.

Fhuqking LAUGHING!................