Consistently inconsistent run-out?!

[Wheres-Waldo]

I’ll keep this simple. And am asking if you experience the same?

I measure cases for run-out at the neck after sizing, and will get 80-90% with satisfactory straightness (.002” or less).

In that same batch I’ll have 10-20% that are over, sometimes up to .004”

Why can’t I get consistency in my sizing?

Shoulder bump is always spot on.

Equipment
-1986 RCBS Rock Chucker
-Redding Type S FL Bushing Die w/o expander
-Accuracy One Gauge/Mitutoyo .0005” Indicator

 

[spife7980]

Are you sure that runout you are measuring isn’t just neck thickness variations?

 

[Wheres-Waldo]

If I’m using a bushing, any hypothetical variation would be on the inside of the neck, wouldn’t it be?

 

[spife7980]

Ideally but I doubt it goes completely in or out, I think the pushed inside or out is a some-is-better-than-none situation.

 

[A&8's]

Is your bushing slightly loose in the die?

 

[47guy]

have you marked the out cases then checked them again after firing and sizing again? also have you marked the out cases and shot them side by side with your better cases to see if it really matters?

 

[clcustom1911]

How well does the ammo shoot?

 

[Mike Casselton]

Is your bushing slightly loose in the die?

^^^^ This right here. The bushing must float.
Also, the speed that you resize can have an effect. Going up slower into the die allows things to center before sizing begins.

 

[Wheres-Waldo]

Is your bushing slightly loose in the die?

Yes, slight enough to hear it click when shaking the die. Not super loose, maybe a few thousandths.

How well does the ammo shoot?

Good enough, I’m satisfied with how it prints inside 500. 1/2MOA typically.

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Essentially, if there is a methodology I’m unclear on that would allow me to be more consistent, I’d like to incorporate it for the sake of confidence.

 

[clcustom1911]

Yes, slight enough to hear it click when shaking the die. Not super loose, maybe a few thousandths.




Good enough, I’m satisfied with how it prints inside 500. 1/2MOA typically.

—————————————————————

Essentially, if there is a methodology I’m unclear on that would allow me to be more consistent, I’d like to incorporate it for the sake of confidence.

If you have the ability and ammo to shoot consistent 1/2 MOA at 500.... I think that's good confidence right there and better than a lot of people in this pew pew pastime.

You can Float your bushing a tad so it can self adjust to the neck of your casing. You could also turn your necks to uniform their thickness.

But, again.... point of diminishing return with your ammo when your rifle isn't a super duper 1000yd F Class, bonded/glued together, super tight tolerance, etc.....

1/2 MOA at 500 is excellent.

 

[Tokay444]

Have you neck turned?

 

[chevy_man]

Quit worrying and shoot more.

Unless you're neck turning you'll just drive yourself nuts.

 

[Wheres-Waldo]

I have the ability to neck turn, but that would lead to less shooting and more time at the loading bench.

I do not want to start turning necks again

I 100% agree, less everything else, more shooting.

 

[A&8's]

I have the ability to neck turn, but that would lead to less shooting and more time at the loading bench.

I do not want to start turning necks again

I 100% agree, less everything else, more shooting.

Turning is a 1 time thing. Grab a 12 pack, spend a few hours turning necks and be done with it.

If you're checking run out, you're already down the rabbit hole. Might as well make yourself comfortable down here.

If nothing else, sort the ones that have run out, shoot them, size as usual, measure run out. If still present, turn em' down. If it's a die thing, you'll eventually get thru them all. If it's a brass thing, you'll be thru them too, eventually. lol

Or throw the dial indicator on the back shelf and just 'choot 'em.

 

[47guy]

Or throw the dial indicator on the back shelf and just 'choot 'em.

THAT^^^RIGHT THERE!!

 

[Dstoenner]

Are you lubing the inside of the necks. I had your issue till i used grafite to lub the inside of the necks of my 308, 260 and 6 BR. That is then the best you can do using a inside of the neck sizing button.

Your next level is to turn the necks, loose the sizing button and go to a bushing die.

The next level is to buy a forster FL sizing die and send it to Forster and have it honed to the size you need.

I am at level 3 (because i am anal) for my f-class rifle and with my 6x47 i get 95% .001 tir and the rest not worse than .002.

I also load in batches of the same case lot. I sort the loaded ammo and keep the 1’s and 2’s for competition. The 3’s for 100 yard practice and anything else that adds up to 5 rounds to shot across the chrono so i have a velocity for this batch.

HTH

David

 

[Wheres-Waldo]

I’m using a bushing die without an expander button, so nothing going inside the necks.

 

[Dstoenner]

I’m using a bushing die without an expander button, so nothing going inside the necks.

Sorry, i misunderstood the rattling comment was about your bushing not a button. I have been in your shoes and the only way you can improve your runout is to turn necks. Before i retired i worked from home and would have these long conference calls. I would mute my headset and listen while i turned necks. Now i am retired so i turn necks to the radio.

David