Waste of time to discuss with them, they will always call white to be black. Red svolocz.
Are guys are full of ... emotions. And I can understand this. You are overhelmed by your potato-bros propaganda. Anyway, it is difficult to ignore facts:
1. German pistols of THREE DIFFERENT CALIBERS
2. German ropes
3. Abrupt stop of German investigations in 1942
4. Numerous evidence from locals that execution was performed by Germans
5. Medical expertise and exgumation by Dr. Burdenko stating that killing took place in 1941 (i.e. by Germans)
6. Discovery of documents on bodies dated aug-sep 1941 (Smolensk was occupied by Nazis by this time)
Body of evidence agaisnt your version is growing every day but of course thinking is difficult and truth is not welcomed in Poland. It is easier to scream and whine and blame Russia for everything and ask, and beg for COMPENSATION.