I'm working on reloading some shells for one of my family members 243 win and I've ran into a snag. I reloaded up a batch of shells to go check at the range and i've ran into a bolt stick i have my coal set with a federal factory load that chambers fine in the gun. Upon inspection of the casing right at the base of the neck i noticed where it seems like it pushed it out it's like a small ring the whole way around the base of the neck like it bubbled out. I have my dies set properly and i've reloaded for many other calibers and never ran into this problem. Any ideas what it is or how to fix it?
I'm using rcbs group A Full Length resizing dies. The problem seems to be coming from the sizing die.

A picture would be helpfull. It may be the sizer is not fully sizing the full length of the case, if the neck expands some from firing and the case is not going into the sizer all the way it could leave a bulged ring around the neck.

From the looks of that picture, it appears that your sizing die was not set all the way down. When you set it, did you have your press ram up at its highest point, screw thed die down until it contacts the ram (with shellholder), then lower the ram and screw down an additional 1/4 turn. This causes the ram to 'cam over' against the die ensuring the entire case gets sized.
If you did as above, it is possible that the die is not machined correctly. Is this the first batch of cases you reloaded with this die?

I have the die down 1/4 turn so it will cam over thats whyI cant make sence of any of this. I guess ill call rcbs and see what they have to say.

I agree with BRONCO..it looks like you die is not down far enough..your only partially sizing the neck and if you have a tight chamber and shooting high pressureloadsit could be causing it to hang up or stick.. I actually do this in my varmint guns, they seem to shoot alot better and as a matter of fact I only size them to the base of the bullet..but I shoot well under maximum pressures and have never had a problem with them sticking..maybe the die is not cut correctly??...borrow anyother die and see what happens when you place the bottom of the die flush with the top of the shell holder...

The expander ball is not the correct size.......

To me it looks like a case neck 'donut.'

The brass in the lower part of the neck and shoulder is thicker than in the upper part of the neck. When firing, especially with hot loads, the brass flows from the thicker shoulder to the neck and the brass becomes thicker at the jucture of the neck and shoulder. The problem becomes worse when you FL size the brass by RCBS instructions that tell you to 'cam over' the sizing die which sizes the brass back to SAAMI specs rather than something closer to the size of your rifle's chamber. When the brass is fired again, there is even more case stretching and flow into the neck until the neck is actually constricted and you end up with overpressured loads on your next firing.

Back off on your sizing die- size your brass just enough that it chambers easily, no more. I would start about 1/2 turn or more off the shell holder and size the brass down in 1/16th turn increments until it chambers easily and the sizing die completely resizes the neck portion of the brass. You might have to bump the shoulder back a bit before you get to both considerations, especially if you have a tight chamber on your rifle.

I would just dump the brass with the donut necks in the recycling bin and start over with new brass. You can neck turn them to remove the neck donuts, but the time and expense really isn't worth it for a common chambering with readily available brass like the .243.

I would like to hear the outcome of this. I have never seen such an issue. But I generaly only neck size or collet size. Wonder how many times this brass was loaded.

I had a couple come out of a seating die that way . Idiscovered a trim length problem . Out on a limb possibly a length of chamber vs case . I think thats a reach . Ive never seen thick necks save for LC Match or formed brass ie 22-250 from 308 .

Issue resolved thanks for you're help fella's. I ended up screwing around with it for quite some time but I solved it. I talked to a few of my buddies who reload and one of them suggested like briman to back the die out 1/2 turn and try it so i gave that a shot it still didn't quite solve it so i ended up backing out 7/8 turn and bingo the donut went away and now they chamber fine. Seems a little odd to me but its working. I threw all of that brass away. The brass i was using was once fired remington factory brass what struck me as odd to begin with is that once fired 243 brass needed trimmed they were right at max thats the first i ran into that coming from a factory load. Any who i loaded up a couple combo's and the gun really seems to like 41.5gr of IMR4350 book max after building up of course with CCI 200LR primers. I was able to stuff em in right around 3/4" at 100yd which pleased me for only tring 3 different loads. I'm just glad to have the whole issue outa my hair. Thanks for you're help.