Runout after bullet seating?

[texasveteod]

OK, have a quick question or 2. I just started loading for my .308 Savage and have a question about run-out. I am loading 1 fired FC brass from the GMM rounds I purchased and fired. I Full length sized and bushing neck sided using a Redding die with the expander ball removed. Anyway of the 50-60 cases I resized I was able to get about 40 with .002 or less run-out, I picked the 30 best, 22 of which had less the .001. But after seating with my Forster die, I started getting rounds as high as .006. Of the 30 I loaded, 10 to 15 had .002 or less; but the rest were mostly at .004 or above. There was a couple a .003 but a majority were at .004/.005. What can be causing the run-out, neck imperfections?

Concentricity gage is a Sinclair and is being check just in front of the ogive.

Federal brass
Sierra 175 MK
Hornady single stage press
Lyman holder
Forster Micrometer die
Redding full length type S with expander removed

Thanks in advance.

 

[Wildfire]

I would put that expander ball back in and try it.
It should help keep things centered better.

 

[cornfused]

Try this: seat the bullet about 1/3 of the way home, retract casing and rotate 1/3 revolution, seat another 1/3 of the way, rotate 1/3 revolution and fully seat. This will usually minimize run-out caused by bullet seating.

 

[243winxb]

The size stamp on the Redding bushing needs to face the case mouth.

On seating the bullet, the neck only needs to expand .002" Dont over work the brass by sizing to much.

Try sizing less of the neck. In 243 i only size about half way down the neck. (Single shot rifle)

If not neck turning, do use the expander. But lube the inside of the case necks. Look for light drag, as the bushing pulls thru the necks. A tiny bit of lube on the outside of necks is needed also..

 

[RecoilRob]

Are you sure the necks are uniform thickness? I've turned a bunch of them and found that some needed material removed from one side to make them exactly even, and expecting the bullets to seat without runout after neck sizing a lopsided neck might be frustrating.

 

[243winxb]

Sizing unturned necks with a bushing and no expander , moves the variation in neck wall thickness to the inside . Bullets may act as an expander, when none is used.

May or may not make a difference.

 

[texasveteod]

The size stamp on the Redding bushing needs to face the case mouth.

On seating the bullet, the neck only needs to expand .002" Dont over work the brass by sizing to much.

Try sizing less of the neck. In 243 i only size about half way down the neck. (Single shot rifle)

If not neck turning, do use the expander. But lube the inside of the case necks. Look for light drag, as the bushing pulls thru the necks. A tiny bit of lube on the outside of necks is needed also..

Good to know about the stamp, I actually have mine facing up. For sizing, I don't expand anything; I simply size down the neck to .001 less than a loaded cartridge and bump the shoulder's back about .001-.002. That is all that's done other than the body. I don't\haven't neck turned so maybe that is what's causing it. I also found that working the lube on the neck seemed to help. Initially I was just spraying the case, but when I started spraying and rubbing it in, it became smoother and less run-out.

Are you sure the necks are uniform thickness? I've turned a bunch of them and found that some needed material removed from one side to make them exactly even, and expecting the bullets to seat without runout after neck sizing a lopsided neck might be frustrating.

Nope, not sure at all. This was my first batch of .308 with bushing die, so I'm new to this method and am still learning and working out the process. Next tool will be a neck turning, any advice on a good one?