11-13-2021, 03:10 AM
Yes, I have fireformed 220 Russian Lapua Brass to make 6mm ARC brass. What I did is as follows:
1) Ran the 220 Russian brass through a .241" mandrel to open the neck to 6mm. Just some neck lube needed.
I used sizing wax for this step. It was lightly brushed into the necks before using the mandrel.
NOTE: If not opened to 6mm first, the brass fits too loose in the chamber for a cotton or wax plug type fireform. It will need
to actually shoot a 6mm bullet. This is because a false shoulder will need to hold the brass in place during firing.
2) I then began loading with a starting load of 27.0 grains of CFE223 and loading a Sierra 100gr bullet. I did no work on the brass
to this point, except to open the neck, then I primed, placed powder and seated the bullets.
NOTE: A lighter weight bullet will mostly not work for this. The reason is that the bullet needs to be loaded long enough
so to lightly stick the bullet in the lands on bolt close. I do mean slightly into the lands. The bolt needs to just feel a bit
of friction when closed. The cartridge needs to be held in place by the bolt face and the bullet in the lands just a bit or it
will move too much in the chamber to fire. The lighter bullets I have would not allow seating deep enough to work correctly.
They seat too shallow and basically will simply fall out of the brass at the long load length needed in my rifle's chamber.
So, get some cheap longer heavy 6mm bullets to do this.
3) I then took the rifle to the range and shot the rounds. They formed as good as they get. They also came out at 1.495" OAL
and only needed to be trimmed a little to be perfect. Other than having use up primers, powder and bullets, the fireforming was
easy to do and gave me no trouble at all.
1) Ran the 220 Russian brass through a .241" mandrel to open the neck to 6mm. Just some neck lube needed.
I used sizing wax for this step. It was lightly brushed into the necks before using the mandrel.
NOTE: If not opened to 6mm first, the brass fits too loose in the chamber for a cotton or wax plug type fireform. It will need
to actually shoot a 6mm bullet. This is because a false shoulder will need to hold the brass in place during firing.
2) I then began loading with a starting load of 27.0 grains of CFE223 and loading a Sierra 100gr bullet. I did no work on the brass
to this point, except to open the neck, then I primed, placed powder and seated the bullets.
NOTE: A lighter weight bullet will mostly not work for this. The reason is that the bullet needs to be loaded long enough
so to lightly stick the bullet in the lands on bolt close. I do mean slightly into the lands. The bolt needs to just feel a bit
of friction when closed. The cartridge needs to be held in place by the bolt face and the bullet in the lands just a bit or it
will move too much in the chamber to fire. The lighter bullets I have would not allow seating deep enough to work correctly.
They seat too shallow and basically will simply fall out of the brass at the long load length needed in my rifle's chamber.
So, get some cheap longer heavy 6mm bullets to do this.
3) I then took the rifle to the range and shot the rounds. They formed as good as they get. They also came out at 1.495" OAL
and only needed to be trimmed a little to be perfect. Other than having use up primers, powder and bullets, the fireforming was
easy to do and gave me no trouble at all.