To be honest, make a .50 caliber bullpup AK isn't a really good idea, at least in that way. Also now i see many misakes in construction, barrel is not coaxial with bolt, missing cheek protection over a reciever, strange mag design, etc. Maybe sometimes i redraw this.
I dont know how about ponies, but for humans this rifle is not very comfortable. Inarticulate trigger, a lot of powder gase near the face, difficult using for left-handed and more. I think ponies kan use bullpup firearms, but not this.