Is there any difference between the 6mm BR Remington and the 6mm BR Norma cartridges ?   Do the both use the same cartridge brass ?

Thank you for that.  I was searching last night and think that I discovered that the 6mm Dasher also uses the same brass but it fire forms pushing the shoulder forward.  The case length shows the dasher being .020" shorter .  I guess that happens because the body is being lengthened and the neck shortened in the fire forming process.
The reason I asked is that yesterday I acquired 200 rounds of primed Remington brand small primer 6mm BR brass.  I think I will start looking for a barrel for my TC Encore with preference for the Dasher.  The Dasher shows about 200 fps higher velocity with all bullet weights over either the Rem or Norma BR.