I an not agree at all here, as you are focusing on the wrong things.
First a gun that will shoot less than an 1" at 25 yards is superaccurate, very few guns do that.
If the gun shoot that tight at 25 yards it will also shoot extremely good att 50 yards.
That is basic physics, at least as long as we not are talking wadcutters.
The difference in sightradius is very small.
In the book Experiments of a handgunner the author did trials with a superaccurate gun, he did shoot it with its normal 7" sightradius.
And he did extend the sightradius to 14".
There was no differnce at the target, same accuracy.
I have built a number of 12" barreld revolvers for our swedish field magnum target shooting.
But honestly a lot of the competitions have been won by 6" guns, and those guys shoot out to 200 yards.
For the real experinced and extremely good shooter the really long sightradius can surely be a help, but for the casual shooter who not can hold 5 rounds at 4" at 25 yards everytime he shoots it have surely no effect at all.
Regards HÃ?Â¥kan
http://www.vapensmedjan.com