I don't know if there are any competitions for air pistol out at 20/25 yds/mtrs, but, like you, I enjoy stretching their legs out to that distance.
I regularly use my .22 Webley Tempest and CP1 at 20 yards and can usually score in the 80s, and sometimes in the 90s.
I stock up on targets every time I go down to Bisley.