I have an an issue whilst using a PSO-1 Scope attached to an AKM. Whilst standing or crouching, I can see through the scope and iron sites absolutely fine. When prone however, I cannot see through the scope as there is clothing or something blocking the sights. Iron sites are fine to use while prone, but switching to the scope using LB means that the view through the scope is blocked. I was wearing a SPOSN Tortilla Backpack at the time, it may or may not be limited to that backpack.