Just started a new loading cycle on some 6.5 Creedmoor brass. I'm loading for a new barrel so upon checking a fired piece of brass in the new chamber I found that the shoulders needed bumping.

The last ammo I produced was the best I had ever made concentricity-wise. .002" runout was the worst. Well I had to re-adjust the die to bump the shoulder a bit for a slight crush fit in the chamber. I did and I was off and sizing. I checked some loaded rounds and the concentricity was aweful, some up to .005".

I started at the beginning trying to find out the reason why. I use the Redding Type-S FL Bushing die and Bushing Neck die. I tried with the expander ball, without the ball, the dies in different presses, just the neck die, etc all with really no better luck. Last night I started from scratch again with a fired case. I put the FL die in the press without the neck bushing. I figured I'd just adjust the amount of shoulder bump needed first, then add the bushing to try to eliminate any problems one at a time.

I remembered reading somewhere about setting the expander ball. They said to size a case on the downstroke with the expander loose, then on the upstroke stop just when the expander is entering the neck at the shoulder junction. At this point, tighten the lock nut on the expander/decapper.

I did this a few times checking concentricity with each piece of sized brass at the neck and made the adjustment a few more times until runout got as low as possible.

Has anyone any experience with this or a better way?

I'm pretty much a "rock and a rusty nail" sort of reloader but I do have a question: If you are letting your resizer ball "float" on the down stroke, why are you tightening it up on the up stroke?? Seems like the upward pressure and the fact that the neck is held in place, the resizer would center itself and the upward pressure would keep it going straight as it passed through the neck.

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Originally posted by wasbeeman:
I'm pretty much a "rock and a rusty nail" sort of reloader but I do have a question: If you are letting your resizer ball "float" on the down stroke, why are you tightening it up on the up stroke?? Seems like the upward pressure and the fact that the neck is held in place, the resizer would center itself and the upward pressure would keep it going straight as it passed through the neck.

I thought that too and tried it, but the concentricity was bad.

The purpose of letting it float then tightening when it enters the neck on the upstoke is supposedly for adjusting it to be centered all the time for the rest of your operation. It's a one time deal hopefully, till you screw it up somehow by adjusting how much neck you want to size.

There's another thing.

I don't decap with the sizer, I use a dedicated decapping die. Therefore I adjust the decapping rod with the expander button so it is way up inside the die since it doesn't need to punch out a primer.

Could this be a problem or should I leave the rod in its full length "decapping" mode or will either have any effect on concentricity? Trial and error?

Oh, I didn't know you did it only once. I thought you meant that you loosened and tightened the resizer on every case. (that's what happens when dumazzes get outside of their comfort zone)
But, undaunted, I have another question: If you did deprime and resize in one go, since the resizing ball would be well done in the die so's to punch out the spent primer, wouldn't the flex in the resizing ball stem (try saying that fast) allow the ball to center as if it were floating?
I've always pretty much followed the most conventional methods of reloading but recently, against my better judgement, I bought one of the highly, overpriced gizzies that tell you if your ammo is straight. Mine is, which is something I could have learnt by shooting it. And fire culling as I went. (now you know why I stick to the rock and a rusty nail methods)

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But, undaunted, I have another question: If you did deprime and resize in one go, since the resizing ball would be well done in the die so's to punch out the spent primer, wouldn't the flex in the resizing ball stem (try saying that fast) allow the ball to center as if it were floating?

I might try that next.

IMO you're chasing your tail if you trying to get low runout if you are using a die with an expander or a bushing die if you don't do a full outside neck turn. The expander is off center most of the time and puts a lot of stress on the neck pulling it out the neck which most times will increase runout. If you use a bushing die without the expander then all the variances in neck thickness will migrate to the inside of the neck also causing problems with runout if measured on the bullet ogive.

IMO 90% of all concentricity problems can be solved by using a Lee Collet neck sizer and a Redding Body die but they probably don't make one in that weird target only caliber you are shooting . The problems go away enough so that you can really stop chasing concentricity if you get the aforementioned dies. Worth ordering a custom Lee Collet if they don't make one.

Now there are ways to adjust your expander stem to be in the center and stop creating runout and a poster named kraky was famous for that. Do a search using his username and search words like "expander" or "runout" and see what you come up with.

Before I became enlightened about the Lee Collet I went through a phase where I would mark the high point when rotating in the concentricity gauge and then placing the marked case in a specific orientation before resizing. There was always a "sweet spot" where the die would produce less runout.

Read a long time ago that you could center the stem by a modification of your method where you pick a case that was sized and had very little runout, removed the expander stem, ran the case up in the die and then pushed the stem back through the neck by threading it in until it was just past the neck/shoulder junction. Also some have put a rubber washer under the lock nut on the expander to "float it".

I am no longer an expert on your situation since I have graduated past it with the Lee Collet and Redding Body Dies.

I'm sure HC will have some kind of method using baling wire, duct tape and cow manure to help you out though!

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I'm sure HC will have some kind of method using baling wire, duct tape and cow manure to help you out though!

I'll stand by

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Originally posted by rcamuglia:

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I'm sure HC will have some kind of method using baling wire, duct tape and cow manure to help you out though!

I'll stand by

You'll probably have to wait till tomorrow morning since I think HC goes to bed at sundown with his pet rooster under his arm.

Keep fiddling with that sizing stem. You will eventually find a sweet spot where it makes really really good brass for you. I often give 1/24 turn tweeks and check a few brass, tweek again, check a few brass. I also have tweeked some of the stems like hornady that have a tightening collet.
Believe me...there IS A SWEET SPOT. Sometimes you find it right away....sometimes it takes fiddle time.

Thanks kraky! I bet you're right. I also think I just was lucky the first go around when runout was zero!

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You'll probably have to wait till tomorrow morning since I think HC goes to bed at sundown with his pet rooster under his arm.

No doubt about it!

The bullet seating operation is also a key time to explore....Yes a bullet can be seated with run out in perfect brass.

When I measured the runout in the loaded rounds, the first thing I checked was my sizing operation and found a problem there. Hopefully I can fix it then check seating.

I thought HC kept his cock in his hand not under his arm. You learn something new every day.

(the devil made me post that)

Which concentricity tool are you using? I straighten mine out with the Hornady tool and works good.

Am I crazy?

I'm no expert.

I reload for 300wm 7mm and 7-08. The 7-08 is a custom made die and generally has .002 runout. Probably 1 in 10 have .004-.005.

The .300 is consitantly in the .004-.005 range.

The 7mm is generally less than .002.

Is there something I can do within my die on the .300 to adjust it a little bit? I have turned the inside of the necks on the 300 but not the outside yet.

I'm using a Sinclair tool. Competition dies like the Redding or Wilson are the best and will help immediately.

If you size with the expander, the imperfections will be ironed out on the inside diameter and pushed to the outside. At that point, outside neck turn for consistent neck thickness.

Try the adjustment of the decapping stem as above to find the sweet spot like kraky says to eliminate runout