Absoultely. These are like the famed "tanker garands". They are simply not real. There may have been a few experimental models made but, like the MAS 49/56 in the new NATO caliber, they are pipe dreams; maybe even moreso.
It is truly a testament to this rifle, however, that so many attempts to make it "right" were tried. First, the SVT38 was abandoned and the SVT40 introduced which supposedly fixed the problems the 38 was having. Then they made some of them into the AVT which was full-auto. Then the "carbine" was tried. None was really super successful and that's why the Russians closed down production and started remaking M91/30s in the same plants after the production of the SVT40 was terminated. And, all of that was worked around that gigantic 7.62 x 54R round. Amazing story, really. And it's quite a different story than the comtemporary M1 Garand, isn't it!
Rome