In his non fiction book Rogue Warrior, Richard "Dick" Marcinko(CDR, US Navy retired) the founder & first commanding officer of SEAL-6(now called DEVGRU/Development Group) wrote that the SEAL team members would shoot .45acp, 9mmNATO and .38spl/.357magnum handguns at 3"x5" cards on targets at 30 feet.
Reseach by the LAPD found that 28ft was the average range for a MOS(member of service) shooting.
In general most armed citizens will be in critical incidents in extremely close ranges(3-6 feet). I say remember the 3x3x3 rule; 3 rounds at 3 feet in 3 seconds.
When I go to the range I shoot at about 30 feet but practice at 3 feet or contact range too. It's good to know exactly how you & your weapon will work at both distances.