Don't know about the availability.
And I say, anyone who refuses to own a gun or learn to use a gun or allow others to own and learn to use a gun for the protection of life, is mentally ill, or unbalanced. Because they have somehow suppressed the natural survival instincts normal humans are equipped with.
That looks like interesting round. What kind of FPS were you getting ? How was the accuracy ?
Be a great SMG round.
Why not try and find a 22 Reed Express barrel for your CZ-52. The 22 Reed Express is the 7,62x25mm necked down to 22 cal and according to Reed "gives betterballistic performance than the FN Five-seven's 5,7x28 mm with the same barrel length". Reed made these 22/7,62x25mm barrels for the CZ-52 and you can buy the cartridges or reload them.
22 Reed in CZ-52: 30 gr bullet at 2513 fps, 40 gr bullet at 2200 fps, 50 gr bullet at 2080 fps
Look on Poly gun bags web site. They have had sabots on there the other days for 30 cal. down to 22.