BTW, the running boar/running target versions of the FWB 300 are quite rare and worth a nice sum of money in good condition.
It's also interesting to hear that the recoil dampening works with those power levels as well. New/after a respring/service these things seem mostly to be a bit over the German power limit but it doesn't seem to be THAT serious over there. I don't know the logic, but while the limit is 7.5 Joules a rifle doing e.g. 8.2 Joules after a service doesn't seem to require immediate derating. At least when you're using standard parts.
Cheers,
-Topi