Bullet Runout Issues - Help!

[cjc5062]

Hi all, so I’ve completely gone off the deep end the last few months with precision hand loading. I don’t shoot PRS or anything, but do go out west to hunt every year and shoot often. I enjoy trying to get the most precise loads and accuracy out of my hunting rifles and am just trying to learn as much as possible. I’m focused on 6.5 PRC and 7 PRC at the moment.

In the last few months I have completely upgraded my reloading set up. I’m now running the following setup: Area 419 Zero 2 Press, Area 419 Full Length Micrometer Sizing Dies, Short Action Customs Infinity Arbor Seating Die, Amp Mark II Annealer, Amp Press, Henderson Trimmer, Primal Rights Primer, Ingenuity Precision Powder Trickler with Sartorius Scale, Mitutoyo calipers, Mitutoyo micrometer, Area 419 comparator set, Area 419 Powder Funnel and tube extensions, Accuracy One Concentricity Guage with Mitutoyo dial, and other odds and ends items. I have not yet purchased an Autodod case neck turner, but it has crossed my mind.

I have watched just about every video I can out there, including Primal Rights, Ultimate Reloader, Bolt Action Reloading, F-Class John, etc. and have tried my best to use the same processes in start to finish reloading. I’m currently using new Peterson Brass (sorted to .005” - <.001” neck concentricity), anneal first, then trim/chamfer, brush inside of the neck with nylon brush, powder charge, seat bullet.

I have been able to get down to very good Standard Deviations in my loads (some as low as 3 fps Standard Deviation for 3 shot groups), but cannot for the life of me get consistent or acceptable bullet runout. I’m using Berger Elite Hunter bullets in 140gr. for 6.5 PRC and 175gr. for 7PRC. I take my measurement of bullet runout halfway between the neck of the case and end of the bearing surface (before bullet starts to angle down). My bullet runout measurements range anywhere from .002” to .008”. With the quality of components and tools I’m using, I’m really hoping to get the runout to around .0005” but at this point would take anything less than .002”. I think I may have narrowed this issue to a few things, but would like to get other’s thoughts before I go trying other things:

1. Short Action Customs Seating Die – I’ve heard mixed reviews on the SAC Infinity Die, in that there is too much movement since it is made for any caliber. Thinking of trying Micron dies or anything else that is highly recommended for precision.
2. Henderson Trimmer – The pilot on the Henderson trimmer, while it doesn’t seem to do much to the inside of the neck when trimming/chamfering, I know Primal Rights states the pilot trimmers can impact seating. Although, I know this trimmer is highly regarded by many and used without issue.
3. Change the lubrication for sizing – I currently use Hornady One Shot for lubrication, but this does not necessary get inside the neck well. I’ve heard many shooters using imperial wax as the main lubrication of choice.
4. Neck turning – I have not yet purchased a neck turner, although I’m considering an Autodod. However, in watching various videos, I know getting <.002” bullet runout is very doable without neck turning.

Please let me know if there is anything that stands out to anyone, or if there is something I’m not thinking of. I know bullet runout may not impact accuracy all that much, but its more about the pursuit of trying to get the most out of my loads. It’s also just driving me absolutely crazy lol

 

[Dos Perros]

Are you taking measurements throughout the process? For example, take measurements of unsized brass, after sizing, after seating, etc. I'd even take measurements of factory ammo to get warm fuzzy on your measurement technique.

 

[WeiserBucks]

I used to measure and chase concentricity, then I quit. My rifles are just as accurate as ever.

 

[cjc5062]

Are you taking measurements throughout the process? For example, take measurements of unsized brass, after sizing, after seating, etc. I'd even take measurements of factory ammo to get warm fuzzy on your measurement technique.

Yes, I take measurements at all stages. Before doing anything, after resizing (including inside diameter) and after seating.

 

[Jason Snyder]

How do they shoot?

 

[cjc5062]

How do they shoot?

I’ll get a flyer once every 3-4 shots with the bullets that have a .008” runout.

 

[Dos Perros]

Yes, I take measurements at all stages. Before doing anything, after resizing (including inside diameter) and after seating.

Where do you see your runout growth? Like is it low low low high? Low low high high? Your measurements at different phases will identify which process is introducing the variation.

 

[Jason Snyder]

I’ll get a flyer once every 3-4 shots with the bullets that have a .008” runout.

How much of a flyer? What does the gun routinely shoot? Have you compared a decent sample size of rounds with and without runout?

 

[TaperPin]

The more the case neck grips the bullet the worse runout will be - that can be uneven or lacking lubrication or sizing it too small and requiring the neck to grow a great deal. Annealed or not, some brass will have hard and soft spots - I toss brass if it caused a flier because there can be all sorts of hidden defects working against you. A Wilson seating die and arbor press are what often works the best and those universal seating dies have too many tolerances that get stacked against you. Culling finished ammo with large runout is also just a normal part of reloading - expecting all ammo to be perfect isn’t realistic. I set it aside for fouling shots or offhand practice and mark the case head with a tiny scratch going from primer to edge of rim - anything can be used from a sewing needle, to utility knife blade, to one of those carbide scribers made for marking metal - just a very light scratch. If it continues to have excessive runout a second time it gets tossed.

All this is dependent on what you’re shooting - if you have a factory barrel that shoots above 1/2 MOA I don’t think using the best methods will buy you much. My personal cutoff is 1/2 MOA. Larger than that and I just use regular old school full length sizing die sets unscrewed half a turn so they more or less only neck size - $29 used on eBay. Smaller than that I’ll use a fl bushing die unscrewed 1/2 turn to more or less neck size and separate expander mandrel, paired with Wilson seating die.

Sounds like you’re headed in the right direction.

 

[daddaman]

Hi all, so I’ve completely gone off the deep end the last few months with precision hand loading. I don’t shoot PRS or anything, but do go out west to hunt every year and shoot often. I enjoy trying to get the most precise loads and accuracy out of my hunting rifles and am just trying to learn as much as possible. I’m focused on 6.5 PRC and 7 PRC at the moment.

In the last few months I have completely upgraded my reloading set up. I’m now running the following setup: Area 419 Zero 2 Press, Area 419 Full Length Micrometer Sizing Dies, Short Action Customs Infinity Arbor Seating Die, Amp Mark II Annealer, Amp Press, Henderson Trimmer, Primal Rights Primer, Ingenuity Precision Powder Trickler with Sartorius Scale, Mitutoyo calipers, Mitutoyo micrometer, Area 419 comparator set, Area 419 Powder Funnel and tube extensions, Accuracy One Concentricity Guage with Mitutoyo dial, and other odds and ends items. I have not yet purchased an Autodod case neck turner, but it has crossed my mind.

I have watched just about every video I can out there, including Primal Rights, Ultimate Reloader, Bolt Action Reloading, F-Class John, etc. and have tried my best to use the same processes in start to finish reloading. I’m currently using new Peterson Brass (sorted to .005” - <.001” neck concentricity), anneal first, then trim/chamfer, brush inside of the neck with nylon brush, powder charge, seat bullet.

I have been able to get down to very good Standard Deviations in my loads (some as low as 3 fps Standard Deviation for 3 shot groups), but cannot for the life of me get consistent or acceptable bullet runout. I’m using Berger Elite Hunter bullets in 140gr. for 6.5 PRC and 175gr. for 7PRC. I take my measurement of bullet runout halfway between the neck of the case and end of the bearing surface (before bullet starts to angle down). My bullet runout measurements range anywhere from .002” to .008”. With the quality of components and tools I’m using, I’m really hoping to get the runout to around .0005” but at this point would take anything less than .002”. I think I may have narrowed this issue to a few things, but would like to get other’s thoughts before I go trying other things:

1. Short Action Customs Seating Die – I’ve heard mixed reviews on the SAC Infinity Die, in that there is too much movement since it is made for any caliber. Thinking of trying Micron dies or anything else that is highly recommended for precision.
2. Henderson Trimmer – The pilot on the Henderson trimmer, while it doesn’t seem to do much to the inside of the neck when trimming/chamfering, I know Primal Rights states the pilot trimmers can impact seating. Although, I know this trimmer is highly regarded by many and used without issue.
3. Change the lubrication for sizing – I currently use Hornady One Shot for lubrication, but this does not necessary get inside the neck well. I’ve heard many shooters using imperial wax as the main lubrication of choice.
4. Neck turning – I have not yet purchased a neck turner, although I’m considering an Autodod. However, in watching various videos, I know getting <.002” bullet runout is very doable without neck turning.

Please let me know if there is anything that stands out to anyone, or if there is something I’m not thinking of. I know bullet runout may not impact accuracy all that much, but its more about the pursuit of trying to get the most out of my loads. It’s also just driving me absolutely crazy lol

I did not see you mentioned neck tension mandrels which I would try before trimming the outside of the neck. Also I agree with the comment already made regarding the LE Wilson in line seater dies. I purchase my own resets for my rifles and have my gunsmith use it for my LE Wilson Seaters as I buy blanks for him to chamber and match my rifle.

 

[Vern400]

Mandrel expand with imperial die wax
Anneal
Lube your bullets before you press them in
Make dang sure you've got a good id chamfer on your neck. The bullet should just glide into the case. If it feels notchy going in, it ain't right.

I don't think neck turning is going to help you much.
If you think about it, (and do / measure it) neck turning does very little for you with a standard chamber.....UNLESS you have thick spots in your brass on the neck. I turn at 0.0145 neck thickness which is 0.0005 less than nominal. The only time it helps my accuracy is when the brass cuts only on one side. If it cuts all the way around, it doesn't change Jack. For me. I can make Old lake City brass shoot like premium stuff if I put enough work into it. Or I can just buy Lapua brass.

The biggest improvement I ever got with the crappiest brass I ever had was 0.25 MOA improvement from neck turning. And that was on a sample of 20 + 20 cartridges which is not enough really.

 

[Finaddictions]

I’ve chased concentricity for a long time. The comment above at measuring at every step is incredibly accurate. It’s how you narrow down where the runout issue are developing.

With that said, if you’re truly averaging .002-.008 you’ve probably maximized your current system. For most that’s pretty concentric ammo. I’d be willing to bet a substantial amount of cash that it’s your seating die that’s inducing it. The dies I have had the best luck with at getting the lowest runout are either the LE Wilson seaters, or the Redding Micrometer Competition Seaters. They both create very straight ammo.

Neck tension also greatly plays into concentricity. The more neck tension you have, the greater possibilities of runout exist. I find that .0015 to .003 seems to be the sweet spot for low consistent run out. This is achieved by using the correct bushing when you size. I don’t mandrel, because if you’re using the correct bushing your neck tension is already set. Running a mandrel through really accomplishes nothing but an extra step, and you’re adding one more touch point where you can add a little more runout to your system.

I do mandrel new brass, because it is generally way over .003 neck tension which does add runout. Also, make sure you have the correct seating stem. For long skinny tapered bullets use the VLD stems, or again you’ll induce runout. If your loading hunting bullets, then the standard stems work great.

I also dry tumble new brass. This helps lubricate the inside of the necks. This greatly helps with seating force, which helps with runout. You don’t need to tumble them for long.

Finally, no matter how hard you chase this, it is hard to not still have a few cases have a small amount of runout. I can keep them very consistently under .002-.015 with a lot with almost zero runout, but will still have the occasional .003-.004. Anyone who claims to have less is either lying to you or measuring such a small sample size as to not truly represent the average. The only way to now beat this small amount of runout is to measure the consistency of the neck walls. You’ll find some variations in the thickness of the necks and that’s the final piece that can induce the small amount of runout left in the system.

A final aside… to measure concentricity, you should measure it at the bullet ogive. That’s where the bearing surface ends, and the bullet begins its taper to the nose. Also, I’ve never seen a .004 show on a target.

 

[wapitibob]

You don't need to turn necks but if your brass varies in wall thickness at the neck, like my ADG 7PRC does, you need to run a mandrel thru it after neck sizing or your neck tension will vary. I never needed to do that with Nosler but this ADG varies almost .002 in wall thickness. That's a variance of almost .004 on the neck ID after using a neck bushing (minus some spring back).
I've never measured runout on a loaded cartridge.
I use .004 neck tension.