Heinrich Keller of Frauenfeld, Switzerland, aged 40, representing his country with a specially constructed 170mm-barreled W+F 1906/29 7.65mm Luger in his first international event, the 1949 ISSF competition in Buenos Aires.
Compounding of shooting errors becomes minimized in the hands of a good shot firing an accurate handgun. On the other hand, a shaky shooter given to habitual deviation from his target cannot reap much of a benefit from increased precision of his firearm. Generally speaking, the human factor counts for more than mechanical looseness in missing your target. For a careless shooter, shot dispersion stemming from his error tends to exceed its dispersion owed to the mechanical looseness of his gun. But aside from that, there is no sense in the notion of not needing a gun that shoots better than oneself. Even the beginner will visibly benefit from choosing a more accurate arm.
The original target of Keller’s fourth pass in the ISSF championship shows a perfect score of 100. It caused a sensation during that event, for no other shooter had managed such a result thus far. His overall performance in competition resulted in 10-shot targets that scored 96, 88, 95, 100, 88, and 92 points, adding up to the same 559 points that he had scored in preliminary training, achieving in each instance the best result of any shooter. Keller’s skill earned his 1949 ISSF title of World Champion in the 25m center-fire pistol event.
In the end, it is as likely as not, that all variations in the accuracy of your aim and consistency of trigger letoff and follow-through, within a given string of shots, will stack up in your favor. Statistically, this stroke of luck will arrive exactly as often as the occasions whereupon all of these variations stack up against you. With your personal best groups and your personal worst bookending the Bell curve, any single test target fired offhand will most likely fall the middle of the distribution. Its deviation from your personal average might be attributable to your mental or physical condition of the moment. But let us suppose that you could constrain these parameters. You might be able to do so by collating such deviations with self-reported or physiologically assessed evaluations of your fitness to shoot. Then the remaining differences would be due to subjectively inexplicable and objectively unpredictable variations of brute luck. In other words, pointing out a few targets shot offhand tighter than they come out of a machine rest day in and day out, proves little about the intrinsic precision of your gun or your skill as a shooter. The real mark of your skill is consistent achievement of offhand shooting scores that lie within the limits of mechanical accuracy of your gun.