resizing the 243

Will an empty case chamber in your rifle and the bolt close with relative ease?

What brass, the rim maybe a little big and shouldn't affect to much.

@Rocky1954 welcome to the forum. Can you post pics could be several things. Is it new brass or previously fired? Older, work hardened brass resists resizing more than new or once fired. Could be the die isn't set low enough to completely resize casing. A picture would help so we can see what the issue might be a little better.

How long are your cases. Should be no longer than 2.045 in from base to top of neck.

You can check the rim area by inserting the case backwards into the gauge. If not oversize, the case rim will likely slide in at least a small amount.

Most likely the case shoulder is too far forward. If that's the problem, you can probably correct that by turning the die in another 1/8 turn or so. In doing so, you will feel a slight interference between the shellholder and bottom of the die at the top of the ram stroke (with no case in the shellholder).

When actually sizing a case, you can also check to see if the shellholder is touching the bottom of the die at the top of the stroke. The resistance of case sizing can affect the shellholder to die bottom distance at the top of the ram stroke.

After trimming, chamfer and deburr case mouth.

Before full length sizing, lube inside the case neck. Lube outside case body. No lube on case shoulder.

Set Fl die so the shell holder contacts bottom of full length die.

Make sure you have the correct fl die.

Try 1 pieace of brass

1) Cartridge gauges are irrelevant unless you are producing generic ammo for an unknown host of firearms. If your ammo closes cleanly in your rifles, then the die is set correctly. Sizing to yield 2 thousandths shoulder bump in your actual chamber is far more productive than sizing to fit a gauge. You can’t fire the ammo from the gauge…

2) If the FL sizing die is hitting the shell holder early, before it sufficiently sizes the cases, then you may need a different shell holder. Some brands of shell holders are simply deeper or shallower than others, so cases aren’t sized as small or as far when using the shallower shellholders. Redding even offers multiple depths in their competition shellholder sets to allow even greater control of sizing headspace and body diameter. One of my rifles is a tight chamber, and I can’t close my bolt on cases sized with the wrong shellholder - as deeper shellholders simply don’t allow sufficient sizing down of the case - it happens.

The shoulder bulge on the 2 bottom ones, look like they were run into a seating die, and case mouth hit the crimping ring?

Clean carbon off fired brass with fine steel wool, before sizing. Then lube case

I looks to me like you tried to bump the shoulder in a neck sizing die....

Rocky1954 said:

Any ideas

Click to expand...

Shoulder buckling like that usually has only happened to me during seating. Too much neck tension, or setting too much crimp so the bullet is moving too much after the neck has been anchored into it. Effectively, crushing the shoulder becomes easier than moving the bullet in the neck.

Are you short on cases? Might be able to salvage those by annealing the necks and running them back through the sizer die. Back the ie out run ram to top of stroke the turn the die until it contacts shoulder, then adjust down till the bulge is gone. Only have to make it chamber in your rifle, it's OK if it looks a little funny it will fire form back into shape on its next firing.

I have some severely dented 5.56 cases that I'm processing right now that look terrible a couple were almost completely flat that mostly went back into shape. Should have taken pics.

If you dint know what annealing is or how to do it there are videos, different types of machines, that will process a lot in a short time frame, but I use a plumbers propane torch, touch yhe flame on the neck shoulder junction for about 30 seconds hile rotating case in the flame you can watch the heat ring move down past the shoulder. Let it extend a short distance past the shoulder and then let it cool off. Hold the base of the case with an oven mit to avoid burns on your fingers and DONT EVER heat a case with a live primerin it, it will detonate. Ask me how I know.