Kiwi bloke,
I don't think different chokes would be much of a problem with used full length einstecklaeufes. The act of adjusting the point of impact from the muzzle should make up the difference. Differing barrel lengths can be a potential problem. Maybe some full-length ELs can be shortened, but it would be pretty hard to lengthen one. If the shot barrel is only a little longer than the EL, maybe the adjustment screws can be reached with common or longer "Allen wrenches". If I could find enough cartridge cases I agree with you that a full-length EL in 6x70R would be handy. Failing availability of cartridge cases, 5.6x50R would be my second choice.
Mike
