Hello Ken,
I've been shooting for a long time and I do know about gun fit. I am not the only ex Blaser owner to comment about perceived recoil and F3's.
I bought one of the first ones in the U.K. and had to use a small mallet to open the top lever at first, due to the angle of the bite. The best one I've owned was a Mk 2 with the trigger upgrades fitted with a Trap fore-end but it still thumped me.
A friend had bought a new Pro sport and I had a shot with it and I thought I'd treat myself to one but after a while I wished that I had not as this one walloped me too.
I then went down the K80 route as these were for me recoil free, just due to the weight but I found it hard work on some stands as I'm no longer a spring chicken.
I then tried a Kemen, a mate used to have one years ago, the recoil level is very, very, low and it really handles very well and weighs just 8lb 2oz.
Blasers in the U.K. are overpriced, when they were first imported they were about the same price as the 682 Beretta, not now though.