Match directors have to decide what power floor they are going to accommodate.
In my IPSC days, 'Pepper Poppers' were set to fall if you hit the top half of the large circle with factory .38 Spl. 158 gr ammo from a 4" revolver or 125 gr 9mm out of a Colt Commander. .45 shooters were expected to knock them down if hit anywhere in the large circle and lower.
I have been to a CAS match where a shooter was using .32 mag revolvers and failed to knock over 12" high steel gophers beyond 10 yds. He was told to go home.
Staging 'hard to knock over' targets fails as a technique to keep people honest as the 'gamers' simply load accordingly. If it was up to me, loads would be 'Cowboy', smokeless or BP. Go large or go home .... ;>)