After resizing 30-06 or 375 H&H i find that there remains a slight bulge in the lower part of the neck of the case. What are the causes of this? It does not effect the chambering of the cases.

If you are using a standard sizer die,I think you are sizing too deep. I don't do the "cam over" that a lot of reloaders insist has to be done in order for the brass to chamber. I resize as little as I can get by with that will allow the cartridge to easily fit in the chamber.

is the bulge larger in that area than a fired un-sized case? You might not be sizing the neck all the way down. As long as they chamber you are fine. But if you are using a FL die and it is not fully sizing the neck then you are not bumping the shoulder back on the case either. So after a couple or few more firings that might become an issue with chambering.

quote:

Originally posted by Luckyducker:
If you are using a standard sizer die,I think you are sizing too deep. I don't do the "cam over" that a lot of reloaders insist has to be done in order for the brass to chamber. I resize as little as I can get by with that will allow the cartridge to easily fit in the chamber.

Yes, I am doing the cam-over full resize that could be the problem, will let you know.

After several sizings the case will stretch and the inside corner of the shoulder/neck will move slightly up into the neck.
As the expander is the last thing to size the case that ring will be stretched to slightly under bullet diameter and that might be the cause of that "buldge".

Post a pic. "Oversizing is not the cause" You want the brass to fit the chamber; sometimes that requires cam over and sometimes not. So, it is not an always or never thing. Depends on the caliber, dies, chamber, brass, etc.

What you have there is the neck is not being sized all the way to the shoulder. It's what they used to call "neck sizing" but when the die people figured they could sell an extra die, they started calling it "partial neck sizing" and provided a "neck sizing" die. It does no harm and IMO helps to align the case in the chamber.

I PRESUME your case lengths are within spec!! I think the Dane is right. The ex-pander is pressing out the small mushroom ( doughnut ) after a correct full length resize. From what you say you have no real problem at this time. Seating a bullet too deep , however, could give you a tight chamber fit.
Take the ex-pander out and resize a couple.
If you size as you are doing now ,afterward you can meticulously turn that swell off with your neck turning tool. roger

quote:

Originally posted by dirklawyer:
After resizing 30-06 or 375 H&H i find that there remains a slight bulge in the lower part of the neck of the case. What are the causes of this? It does not effect the chambering of the cases.

I'm kind a interested on what the final results were!! roger

Mark a fired case with a match (blacken it) the run it in the die to the base of the shoulder and lock things up....Your not resizing your neck fully is the problem..but if the case chambers in the gun your Ok just like it is..

Never load a belted case to the belt as that over works the brass and case life suffers..run that blacken case in a bit at a time trying to chamber as you go..when it close snug then stop or I prefer to go a tad more until the case closes with just a smidgen of snugness..I don't use neck sizing for hunting rounds, to many problems doing that with function.

I remember having the same issue with 308 brass.It could happen if neck sized cases have seen too many reloadings.

If it is the first few firings, then you are probably not screwing the die down enough to size the case to the base of the neck.

If it is happening after 5 or more shots, you might have a donut inside the base of the neck due to brass flow.