Ricoh KR 5 Super II and Pancake Pentax smc m 40mm 2.8

Hey guys,

I have a Ricoh KR 5 Super II and use a Pentax smc m 40mm 2.8. Infact i picked up the lens specifically for this body. Thing is when i use the lens, 9 out of ten shots, the mirror gets stuck against the lens on its way up. Cant do anything afterwards. Cant wind on, cant use the shutter, changing focus makes no difference once its locked. only thing that works is taking the lens off and that releases the mirror.

 

I can see tiny chips on the bottom of the mirror now and sort of scratch marks on the back of the lens.

 

When i focus at closer than 10m its fine. Soon as i reach just before 10 m and further, it starts catching. Should this be happening?

When changing focus, the front and the back move in and out. So as i move to 10 and further, the lens retracts into the camera more.

 

Its a K mount lens but the camera is K mount too...

 

you can see the scratches on the back of lens as well as the chips in the bottom of the mirror.

This is puzzling. I've had both camera and lens in the past, but at different times and never used them together. The 40mm F/2.8 didn't strike me as protruding unusually far at the back. There have been reports of similar problems in some cameras, attributed to the mirror moving forward slightly on its tray, due to the adhesive losing its grip over time.