I was unable to duplicate any of the claims in this thread. Is there a particular spot on the Tiger than is vulnerable to the 37mm?
I shot it all over, from every aspect... all the rounds bounce. Granted, I believe this is how it should be based on armor penetration values for the gun, but I am puzzled as to how people can do what should be impossible and blow up Tigers in an M8.
Point blank at 90 degrees in the rear is your best bet. Not sure if armor degradation is modeled or a slight randomness to the penetration, but pound them enough, when close enough, they eventually go down.
Also, make sure you are not carrying a mixed ammo load. For some reason, unlike any of the tanks, the HE is default in an M8. This might account for some of the bounce if you were close.
Best option IMO is to go for tracking the Tiger first. You can do this at a greater range than damaging the tank itself. Once he is tracked, if you are smart, you can fairly easily first track the other side (so he can't pivot), and then even more easily stay out of his oh so slow turret traverse.