Runout?!

[Forester]

I have all of a sudden developed a problem with high runout in my reloads. I used to get very consistant .003" or less with many coming in at .001" or so.

Nothing has changed as far as brass or preparation goes. My cases have .001" or less after they are fully prepped but when I seat a bullet it comes out with .006"-.007" runout. I usually use a Redding competition seater die and I have also tried a standard Redding seater die with the same results.

The press is a Forster Co-Ax and is fairly new and in good shape. I cleaned up the dies well as well as the press, and nothing seems to help.

Anyone have any suggestions about what else to look at? I am out of ideas except to try another press in case something has gotten tweaked about mine.

Before it is even said, I have proven to my satisfaction that runout over .002" does matter, and it matters more the longer the shot.

[ss7mm]

Is it the same seating die as before?

Are you using the same bullet as before or a different bullet?

Reason for the questions is, have you checked to make sure that the tip of the bullet is not being hit by, or bottoming out in the seating stem? You'd have to take the seating stem out to check but if the die/bullet combination is the same as before then this probably wouldn't be the problem.

Do you have measured dimensions of the case necks after prep in the before instances? Do you know the neck thickness before and now? Do you have before and now dimensions of the case neck prior to seating and after seating? Just curious as to whether anything in the neck area has changed. How many reloads on the brass?

And I'll agree with you on the runout. I try and keep mine as low as possible.

[Forester]

Originally Posted by ss7mm

Is it the same seating die as before?

Are you using the same bullet as before or a different bullet?

Reason for the questions is, have you checked to make sure that the tip of the bullet is not being hit by, or bottoming out in the seating stem? You'd have to take the seating stem out to check but if the die/bullet combination is the same as before then this probably wouldn't be the problem.

Do you have measured dimensions of the case necks after prep in the before instances? Do you know the neck thickness before and now? Do you have before and now dimensions of the case neck prior to seating and after seating? Just curious as to whether anything in the neck area has changed. How many reloads on the brass?

And I'll agree with you on the runout. I try and keep mine as low as possible.

I discovered the problem as part of a test to see if neck turning would improve on already low ES. I am using Lapua cases, the neck turned cases had a .014" thickness and the unturned cases ran .015-.016".

I am using the same bullet as before, Berger 168gr VLDs (.308) I ran out of the old lot, so this is a new lot of the same bullet. Bullets are sorted by bearing surface length.

The bullets do not bottom out in the Redding competition seater die, I am not sure about the standard die but I got similar runout readings from both so I am leaning towards ruling out the die.

I think I am going to borrow a friends press and load a few with my dies, if I get low runout on his then I am stuck blaming the press even though I can not figure out how that would have happen.

FWIW, on 20 neck turned cases, 18 had .006" runout and 2 had .007", very consistant and maddening!

[britz]

are you Partial full lenght resizing, full length sizing or neck sizing? Is it a factory chamber. The reason I ask is I have a rem 700 30-06 with a chamber and bolt that are not centered, neck sized cases have a bulge in them which I think could affect runout. However, this wouldn't explain the change in runout for you.

[AJ Peacock]

Is this the first reloading after neck turning?

Did you resize after turning?

Could something in the turning operation have 'tweaked' the necks?

AJ

[Buffalobob]

Have you annealed the necks?

[Forester]

I am using Lapua cases that have been fired either 2 or 3 times depending on which lot, both lots yeild the same result. Cases have not been annealed.

AFTER the cases are fully prepped, I have less than .001" runout on the neck so I believe the problem is not in the prep. Cases are neck sized only with a Lee Collet die.

The neck turned cases were turned, fireformed, turned again and loaded, resulting in incredibly consistant .006" runout. If I only had the problem on neck turned cases I would blame my in-experience in neck turning, but I get the same result from cases that have never been neck turned.

Factory Savage chamber and barrel.

Loaded rounds that I put together a week and a half before these show very low runout. The problem seems to have come on all of a sudden.

I am going to do some measuring on the press and see what I come up with.