Like you, these type of guns never interested me that much but that does look pretty cool.

Would prefer a slightly longer barrel on it though
as the heat from the flash does come back a bit on
short barreled guns like that and it gets a bit
"warm" so to speak - and that was 9mm.

In looking at that gun, it looks like it has hardly
any barrel at all considering what would be taken up
with the chamber of a 7.62 x 39 round.