X-Die progressive press.

[garryc]

They say that after the first loading and trim you can use an X-Die and not have to trim again. So if I use an X-Die in my RCBS pro 2000 for 223 I shouldn't have a case length problem?

[Horseman]

I don't think so but I'd check the reloading section of this forum.

[csmsss]

I am curious how a reloading die would prevent brass flowing into the case neck during firing?

[Horseman]

You do have to trim once after the first firing. From there on out the shoulder in the head of the die will not let the neck stretch while sizing. They do work.

[garryc]

I am curious how a reloading die would prevent brass flowing into the case neck during firing?

It happens more during resizing, they even can get shorter after fired

[Gewehr98]

The brass flows forward during firing, making for a thicker neck.

The expander ball in normal resizing dies swages that out, and the extra brass shows up as a longer neck afterwards.

X-Dies alleviate that problem.

[impalacustom]

I was always under the impression that casings that are necked down(30-06) will need trimmer after multiple firings and straight walled casings (45acp) will shrink after multiple firings.

If this die pushes the swages the brass out of the neck and makes it more uniform length won't that cause a build up of brass on the shoulder and then cause head space problems?

Just curious because I have never heard of the X-Dies.

[30Cal]

If this die pushes the swages the brass out of the neck and makes it more uniform length won't that cause a build up of brass on the shoulder and then cause head space problems?

Just curious because I have never heard of the X-Dies.

No. The shoulder is set back by the die (to the right place if you've used a case gage).

I've used the X-die, and it works, but never spend the time to figure out how.

The X-die will work on a progressive. Follow the instructions carefully as far as initial trimming.

[Vern Humphrey]

The brass flows forward during firing, making for a thicker neck.

The shoulder moves forward during firing -- because you always have a bit of headspace exceeding the actual head-to-shoulder length (if you didn't most cartridges wouldn't chamber.) The case actually stretches just ahead of the web (the "floor" of the cartridge.)

In resizing (full length resizing, that is) you move the shoulder back to it's original position -- resulting in a slightly longer neck. After a few cycles of full-length resizing and neck trimming, you can take a hooked paper clip and feel inside the case and you will find a notch or ring inside the case just forward of the webb. That tells you it's time to toss that case.

Neck resizing won't stretch cases after the first firing -- but can leave you with cases that will go back into your rifle, but not any other rifle.

[totalloser]

I am not fond of them, but they do what they say. Make sure to adequately lube, they like to stick cases a bit more than their conventional counterparts, and once stuck, if you are using the decapper assembly, you can't get it back out to knock out the stuck case. In a progressive, if possible I'd be tempted to run the sizer without the decap assembly so you can knock out a stuck case.

And beware. All it takes is ONE stray piece of range brass to sneak in, and you could be looking at a dangerous overpressure situation due to rifling pinching the case mouth locking the projectile in.

Another method is the Dillon "trim die" that trims the brass during the sizing operation automatically. I put up a thread on this, as well as my sooper dooper modified trim die. I have been MUCH fonder of the Dillon trim die.

And +1 to Vern. That sounds pretty accurate to me.

[vranasaurus]

All it takes is ONE stray piece of range brass to sneak in, and you could be looking at a dangerous overpressure situation due to rifling pinching the case mouth locking the projectile in.

That's why I mark my brass. That way when I pick up brass at the range I know which ones need trimmed and which ones don't.