25.06 bullet/resize problem?

Did you measure the bullets or the necks.

I would tare the die apart what brand die is it.

There's no adjustment on an expander ball in a full length sizing die, the decapping stem can either be up to far so the decapping pin isn't removing primers or its down to far and hitting the case web so the press handle isn't traveling fully. Maybe if the decapping stem is down to far the case neck isn't getting sized back down far enough since the case isn't traveling all the way into the neck sizing area?

I suppose one could wear out the expander ball but to wear it out would mean make it smaller so you would get more not less neck tension.

I guess I would reset the expander ball / decapping stem so the decapping pin is just knocking primer out of the brass and see it this fixes your problem.

What is the OD of your expander?

Should be ~0.002" less than bullet dia.

I've never seen this and I load for 15 rifle calibers, especially since you said you have loaded bullets from this same box.

There isn't a crud ring on the expander ball is there? Polish the ball maybe?

Any chance that you got some bad bullets in the box?

Next I would start measuring, inside neck diameter after sizing without expander ball, inside neck diameter after sizing with expander ball, bullet diameter of more then a few bullets.

The die is resizing the neck but the expander ball is pushing it back out too far. It's possible the the ball is canted due to a bent rod or something, but my solution would be to take out the decapping rod/expanding ball and polish it in a drill with some green scratch pad or some flitz. Not too much, just enough to make it shine.

Either:
1) the ball's too big
2) the bullet's too small
3) the neck's too thin (to be sized down by the die).

Eliminate 3 if you can feel the brass dragging over the ball on the way out. Figure 1 and 2 with a caliper.

ya they are great, most of my dies are rcbs or lee. I think rcbs was working on a precision die set i was hoping to try.

Ya that's weird

Bull Nutria said:

My question to RCBS was how can an expander ball get larger in the die box?

Click to expand...

Have you bothered to measure the ball and bullets yet? Ball should be ~0.002 smaller. . .

If the decapping rod is bent and the expander is being pulled through at an angle I could see that causing an issue. I've bent a couple RCBS decap rods due to the rod working its way down over time and me being too complacent and not paying attention to what was happening.