If you could find some subsonic match ammo that your rifle likes, you most likely could cut that by half or more. My CZ likes Wolf Match Extra.
Make sure you clean the barrel, then foul it with at least 10-20 rounds before getting real serious.
I had to break in the barrel. Yeah, yeah. I know break in is over rated. All I know is, even using the same ammo, after a few hundred rounds it really settled in.