As for forming, I use the .30-06 cases in the full length SIZING DIE . The trick,if you want to call it that, is keeping everything CLEAN,CLEAN,CLEAN!!!!!!! I use a metal polish and clean a batch of a dozen cases.(win/federal/Remington) all seem to FORM equally well.I deprime the cases in a .30-06 die, install the x58 FL die and remove the depriming pin. I reinstall the pin and run the finished case thru the die as a FINAL OPERATION..... I do lube inside neck and outside of case for this FINAL operation..then am ready to reload.
then I apply a SMALL amount of LEE Sizing lube,about 3/8 '' down from shoulder of the .30-06.
it takes a bit of force. I form the neck,about 9/16'' just to '06 shoulder.....remove from die.....CLEAN NECK and shoulder.....clean off old lube and RELUBE FROM AGAIN3/8'' below the shoulder. then I start the case forming....I do it in 2 or 3 steps.....checking case,cleaning it and relubing....
cases form WITHOUT THE LONG DENTS which are caused by even the tiniest amount of lubrication... after several cases,i clean out the inside of the die........
until I started the above ,I WAS denting cases on a regular basis...... yes,its a bit of a production but its well worth it.......I have a WHOLESALE SPORTS STORE and a new CABALAS both within a couple kms. from my home but not much selection of new brass,. so I had to work with what I had.......again the trick is ...keep the cases clean.
I annealed the cases at one point BEFORE forming, neck to about a 1/4 '' below shoulder then water quenched.....no difference ....... have fired a dozen cases 2 times,ready for 3rd. firing......now easy to load ,no split necks.....its a light load....44gr. H4831 with 120gr. nosler ballastic tips. it works in MY rifle. that's a starting load for the 6.5x55 SWEDE. I have seen in an old edition of CARTRIDGES OF THE WORLD, a load for the PORT 6.5X58MM at a heavier charge for a heavier projectile. I am now looking for a 140/160 gr. mold in .265+'' as I shoot 3 diferent 6.5 mm rounds and jacketed projectiles are a little expensive. Cheers pops