It's real!
Hi Guys
The rifle in question looks like its a product of Southern Gun Company here in the UK. It is, as you rightly point out, in 30 carbine and has un underlever cocking mechanism.
Southern Gun Company, manufacture custom AR15 rifles, parts and accessories.
Over here we are not allowed semi-auto rifles except in .22LR.
We are also not allowed handguns. Therefore most of our pistol competitions are now shot with gallery rifles. Our definition of a gallery rifle would be a carbine length rifle chambered in a pistol calibre.
Most common types are western-style underlevers although bolt-action rifles are also common. The rifle above is an example of our gunsmiths' ingenuity in working round our draconian laws and is OK for use in such competitions.
Obviously, the calibre also has appeal for use in practical type shooting up to about 300 yards.
I know it sucks, but it's the best of a bad job for us shooters here in the UK!
By the way, I never voted for 'em!
-Jon, Kings Lynn, Norfolk, England.