bavarianbrit,
I've never tried the PPU bullet, nor the RWS factory one myself. I didn't get the Brno until after I came back from Germany. I use common 50 and 55 grain bullets for informal shooting, but I use 60 grain Nosler Partition bullets for hunting Whitetail. I shot one in the chest, coming straight to me. The bullet was found behind the ribs; it had expanded to about .40 caliber and weighed 48 grains. The Partition bullet is similar to the "H- Mantel" bullet. That bullet was the only one I recovered, on a side shot they penetrate and are lost. I don't know if you can find Nosler bullets, but it seems handloading is more popular there now than when I lived there. BTY the 6o grain Nosler is simi-spitzer, so is no longer than a 50 grain spitzer, and it will be accurate with the 5.6-barrel twist rate.
Mike