If youve already mastered making accurate and consistent headshots at closer ranges, and your skill allows you to be consistent at 25 yards where practice is productive and not ruining your confidence, why not do it?
I think that people don't have a good feel for what it means to be consistent at 25 yards under real-world conditions.
I can shoot sub-6" groups at 20+ yards, standing and unsupported with my subcompact 9mm carry gun. Last time I went to the range I shot 10 rounds of my carry ammo into 5.5" at 21 yards. I've done better than that. I have a 12 shot group at 25 yards that was under 5"--also with my carry gun & ammo. I wouldn't call that amazing, but the range owner definitely looked surprised when I showed him the target and the gun I shot it with.
I'm good to go, right? Not even close. I've shot in a competition that required shooting 10 shots at 25 yards starting from low ready and at a rate of about 1 shot every 3 seconds. A perfect score means keeping all 10 shots in an 8" circle. You can shoot it with a full-sized pistol and I always did. Should be easy after what I just said I could do, right? Well, I have cleaned that course, but not every time by any means. Just adding a time constraint--and not a very stringent one at that, makes a big difference. Even being able to shoot it with a full-sized gun didn't make up for adding the time constraint.
I'm not going to try to rigorously defend the degradation figures below, they are just my gut feel--call them wild guesses, But what is sure is that there is SOME level of degradation for each increase in complexity. Some of them might be too much degradation but most of them are probably too little.
Let's assume that a person can shoot 5" groups at 25 yards consistently with a full-sized pistol under ideal conditions at the range with no time constraints.
Degrade it 15% for changing to a sub-compact carry gun.
Degrade it 15% for adding in time constraints--not getting to take a controlled breath and settle into a solid stance, maybe not getting a perfect grip on the gun, not taking all the time required to align the sights perfectly.
Degrade it 20% for adding in distractions--other objects moving around the target, people screaming, shots being fired.
Degrade it 50% for adding in target movement.
Degrade it 5% for lighting considerations--your sights may not be illuminated properly, the target may be moving in and out of different lighting conditions.
Degrade it 50% for pressure--people getting shot/killed in the near vicinity, perhaps being shot at.
I think that those are very generous figures. For example pressure alone could cause easily groups to double in size or even grow more than that--a 100% degradation in performance or greater. Target movement could easily cause the same kind of degradation, especially for someone who's never practiced shooting at a moving target with a pistol.
But even the numbers above, conservative though they may be make the point. Starting out with consistent 5" groups under ideal range conditions with a full-sized pistol, those factors increase the group size to almost 19". In other words, the difference between being able to make head shots 100% of the time to not really even being certain of making a center of mass shot.