It turns out there was an interesting answer to this and a specific sort of German shooting, a bit like our bell target I guess:

https://de.m.wikipedia.org/wiki/Zimmerstutzen

(In German but you can translate in safari at least, though you do get some comic results, eg apparently the shooting is called “room nozzle”, which I guess sounds better in German)

Some shooters therefore use (sometimes mysterious) means to anoint the balls to improve shooting precision; oiling the balls before shooting is commonplace
I have not tried this myself but will certainly now consider anointing my balls before shooting to see if it improves my performance