There was two men in the PTRD/PTRS team, but it was indeed possible to carry the gun by one man and it often was carried alone. The another soldier was assistent, whose job was spotting and loading the gun (especially goes with PTRD). On the other hand, Solothurn was virtually impossible to be carried alone. Ofcourse also PTRD/PTRS was often carried by two men to ease up the job, but it wasn