Mario,
I don't say you should be shooting 25 yards. I thought you were, when I did that calculation on the sights.
Shoot at whatever range you are comfortable with. The 2 X 2 backerboard you have will be more than enough to 50 yards, since you are getting 3 to 5 at 15 yards, you will still be on paper. Also, you'll see the movement of the sights, if you do get them to move, better at that range. a couple thou will move the ball further at that range. 'Course, the ball will fall more, so you got to have enough paper to catch the falling ball, it will be low on the target till you raise the sights or the sighting point of aim.
If you are allowed to use anything other than paper targets at the place you shoot, I don't know if it is just at the range or if you have a private place, try a coffee can or a milk jug. More fun to see something move when hit than to go look at some holes in a piece of paper.. Some guys like to shoot at coke cans, miss as often as hit, but you can usually see where you missed, a litle right, hold a little left, see if you can keep it moving.
You'll have fun with that, and don't worry if you miss more than you hit, particularly since you shoot one-handed, out of preference.
By the way, if you ARE shooting ALL offhand, you should be shooting from a steady rest on a bench of some sort to zero your pistol. Once you know where the pistol and its sights are pointing, THEN you shoot offhand, and you know off the bench it shoots dead on, and offhand shoots 3 inches right, you are pulling your shots, your hand is clenching on the grip, or you are yanking the trigger. Gotta learn to control that, and practice is the only way. You sound like you are doing that, the practice, I mean. Just keep it up.
And buy a Colt for your next, they are pretty cool shooters.
Cheers,
George
Duncan, the only reason to start close is to get the damned thing on paper, as my military did. Started at the 25 yard range, zero, then 100, 200 300, 500. 100 was to check your 25 yd. registration, 200 offhand was for record, dropped points there, 300 kneeling, did well there, 500 was with 8 inch bulls, did perfect there. You did use aperture sights, did you not, "peeps", not scopes?