OTs-44 Anti-materiel Rifle

The OTs-44 is a suppressed bullpup anti-materiel rifle chambered in 12.7 x 108mm caliber rounds. It's one of rarest russian prototypes, with just 6 images floating around the internet in super hi-res of less than 600x200px and pretty much no solid information about it...
All that is known about it is that some say that there were 4-6 prototypes, 2 or 3 functional. Then that it is not suppressed as you think. Long can in front is mostly to lower volume to be similar to smaller caliber and disguise it be like eg SVD. It have very unique chambering system similar to WW2 Czech bullpup anti-tank rifles SS-41 where whole barrel need to move forward and bolt is pretty much on buttstock, but few discussion or some obscure russian forums say that OTs-44 chamber next round automatically not manually as wikipedia say... Also one info says that cheek rest moves when ejecting round, but that doesn't make much sense(only if it's automatically) so I added flap on the side that open when barrel moves forward at the same time where kicker/ejector pushes round of the chamber.