Do I have a sizing die issue?

[JamesnTN]

Today I started digging into why I can't get my 284 Shehane to shoot any better than it does at 1k. So I began sizing my cases and as I was sizing them for the first time I noticed as the case went up into the sizing die the die would cock at an angle as if the case was going in crooked. I would rotate the die and it would cock at the angle in relation to the rotation. Once I sized a few pieces of brass 002 on the necks. Now here's the kicker, a loaded round runout is only .0005 and less. So do I have a sizing die issue?

I need to check runout on a fired case to verifying the cases are square, unfortunately at the time of catching this I had already sized everything.

Any comments and suggestions is appreciated.

 

[Dusty Stevens]

So a sized case has .002? It sounds like your seating die is staightening it out. Have you tried to float it with an o ring?

 

[JamesnTN]

So a sized case has .002? It sounds like your seating die is staightening it out. Have you tried to float it with an o ring?

The die is floated I'm using a Forester coax press.

 

[potatoe]

Whats the runout on the sized necks? Also I'm not familiar with the coax, do you have a rockchucker (or the like) that doesn't float? If so what about trying the die in both the floating and non floating set up to see which one produces less runout on the sized neck?

 

[Dusty Stevens]

Are you using the universal shellholder or a regular one? Either way it seems your die may be crooked a bit and your seater is working it back straight. May wanna see about that being bored crooked

 

[JamesnTN]

Whats the runout on the sized necks? Also I'm not familiar with the coax, do you have a rockchucker (or the like) that doesn't float? If so what about trying the die in both the floating and non floating set up to see which one produces less runout on the sized neck?

.002

 

[JamesnTN]

Are you using the universal shellholder or a regular one? Either way it seems your die may be crooked a bit and your seater is working it back straight. May wanna see about that being bored crooked

I have the shell holder conversion setup on the press with a Redding shell holder.

I'm gonna remove the sizing bushing and see if by chance it's the bushing

 

[LRPV]

I've never seen a seater die straighten crooked brass. Anyway, .002" total runout, even if it was on your loaded ammo, which it isn't, won't affect much in the accuracy department.

 

[savagedasher]

Take the expander ball of and see what you have. I never seen a die to cause run out. Larry

 

[JamesnTN]

Take the expander ball of and see what you have. I never seen a die to cause run out. Larry

There is no expander ball. This is a custom FL bushing die made for my chamber.

 

[Dusty Stevens]

I've never seen a seater die straighten crooked brass. Anyway, .002" total runout, even if it was on your loaded ammo, which it isn't, won't affect much in the accuracy department.

The way i read it was he had .002 before the seater and .0005 after the seater.

 

[savagedasher]

Take the expander ball of and see what you have. I never seen a die to cause run out. Larry

There is no expander ball. This is a custom FL bushing die made for my chamber.

Bushing must be the reason then. try a bigger one Larry

 

[Dusty Stevens]

Looks like the die is cocking to the side before the bushing and its following it around as he spins it. Must be bored crooked or a bad lock ring. Id be interested if it did it in a regular press

 

[JamesnTN]

I've never seen a seater die straighten crooked brass. Anyway, .002" total runout, even if it was on your loaded ammo, which it isn't, won't affect much in the accuracy department.

The way i read it was he had .002 before the seater and .0005 after the seater.

I have .002 runout on the neck after sizing and .0005 and less on a loaded round measuring at the ogive.

I can't use a larger bushing as is my bullets would never seat they would fall into the case.

 

[JohnKielly]

Has your bushing room to float side to side & lift a thou or two? That seems to be industry standard to ensure that the bushing approaches the neck true.

Any chance you're sizing the neck too much in one pass? Manufacturers recommend only a small squeeze per pass.

 

['Freak]

Have the necks been turned equalizing neck wall thickness? If not turned, how much neck wall thickness variation is there?

 

[LRPV]

I've never seen a seater die straighten crooked brass. Anyway, .002" total runout, even if it was on your loaded ammo, which it isn't, won't affect much in the accuracy department.

The way i read it was he had .002 before the seater and .0005 after the seater.

Yea, I understand the concept just haven't personally seen it happen. I still wouldn't worry about it too much. Check a few fired cases to see how they are. I just think you're gonna find the problem to be caused by something else other than brass coming out of a sizing die with .002" runout, especially when your seating die is making near perfect ammo out of it in the end.

 

[boltfluter]

James,

I think your lock ring is on crooked. I line up my dies by putting a flat piece of ground steel on top of the ram and run up to the bottom of your die to pre load the die. Then, tighten the lock ring. This aligns the die to the ram. Works well for me.

Regards, Paul

www.boltfluting.com

 

['Freak]

How else is it possible that the insides of a case neck ends up positioning a bullet so that there’s only .0005” runout reading relative to the case body, but at the same time he gets .002” runout once the reading is taken from the outsides of the same case neck?

 

[STS]

I'd put the die in the lathe chuck and indicate both ends of the die chamber with a long stem indicator. You'll know real quick whether the die is straight or not.