I ended up 3 weeks ago buying a BRNO ZKK in 5.6x50R in like new condition off an auction site over here with a nice Tasco euro class 3-12x52 scope on it, nobody else had bid on it so the final price including shipping was when converted to US$200. I then did a little more research on the US Bellms site
https://bellmtcs.com/5.6x50rbellm he suggests using a .357 mag carbide die with a larger hole bored out in the center to let the 5.6x50 case pass through, it will then size just the base diameter down to the same diameter as a .357 case which is what the 5.6x50 needs to be too. Still having fun with this caliber, my neighbour has shot around 10 roe deer with my reloads so far and performance has been perfect.
As I had joined the local jagdhorn playing group last Feb I whatsapped on their homepage asking for fired cases and have been given around 120 freebies so far by non reloading local hunters.