Musings on reforming cases

[jhalcott]

I have been using 223/5.56 cases to make 256 win mag(rimless) cases. Every once in a while a case will come up short. Enough so that the primer does not get a solid hit. I can see the difference the case goes into the chamber. This happens once in about 200 cases, not all the same make. I start with weighed cases, then reform, next trim to length. I size in a full length die, trim and debur. Fire form with cream of wheat. One in a hundred require a second strike. Then reloading for real begins!

[Mica_Hiebert]

Segregate by head stamp, you will get more spring back with different brands of brass esp between the thicker 5.56 cases and 223 cases. Anealing before forming may help reduce spring back as well. I would guess if you just neck sized after fire forming you shouldn't have this issue with consecutive reloads.

[Hamish]

Once more, with feeling,,,,

Segregate by head stamp. Seriously.

Different brands have different internal capacities, which affects pressures, along the other stuff.

[jhalcott]

I'm using once fired cases picked up at the range. Many shooters are government (employees) that get lots of ammo to play with. I see them open the boxes and load their mags. I offer to police the brass IF they don't want it. Some of these people CAN shoot! I am surprised by the
different case weights from the different head stamps. My finished cases weigh 83 to 86 grains. Thanks for the replies.

[EDG]

Are you possibly pushing the shoulder back too far with an intermediate die? It can happen real easily if you are using a .30 Mauser or .30 Luger die.

[jhalcott]

I use an RCBS from/trim die. I start with an RCBS SEATER die, then use the file/trim die. After forming and rough trimming, I use a full length sized die.Then final trim. I guess I'll measure them prior to f/f and first full loading.

[fryboy]

Quite often during fireforming the case is blowed out ,this pulls brass from somewhere ,again quite often ( but not always ) this shortens the case
If you have a case gauge and can find the too short ones you can neck it up to the next larger size and then back down leaving a false shoulder to headspace on or fireform with a boolit shoved into the lands thus blowing the shoulder forwards ,but yeah segregate and annealing can be your friend

[jhalcott]

Well I tried some .357 reformed brass. Out of ten rounds , 6 split at the shoulder. All were snug going into the chamber. I reformed about 40 of them and used a lighter powder charge and the 70 grain Sierra blitzking. I even tried some 75 grain cast bullets with Lee liquid lube. They were in 223 cases and shot well.

[cuzinbruce]

I am curious about this rimless 256 Win Mag. Is it used in a regular 256 WM firearm? I have a Marlin Levermatic in this caliber. I have been reforming 357 mag cases and they have been working OK. And some original Winchesters that seen soft in the shoulder. I have collapsed shoulders on some when seating J-words. Same procedures with the reformed 357's comes out fine.