I could never get good groups with my Colt 1911 when we were allowed to own such "dangerous" guns. I later aquired A Smith & Wesson model 66 with 2.5 " barrel, and using home loaded .357 ammo could group well within the black @ 20 yards, and the loads were not all that soft.
I have tried various BB pistols and found that accuracy in general was not too good, only good enough for tin can shooting up to around 10 metres.