Shooting with apertures

[riflejunkie]

Pretty simple but difficult at times.  The trick to shooting with a front aperture is to have an appropriate line of white surrounding the bullseye and everyone seems to like a different amount.  I have shot well when I felt like I had way too much white showing between the bullseye and the aperture ring and I've shot poorly when I felt it was perfect.  Not only is it important that the bull be centered with a consistent ring around the bull but you should also have the globe centered in your sights every time.  The light around the globe needs to be as consistent as the white around the bull.  You are stacking concentric circles.

[ac12basis]

Selecting the front aperture diameter is a confusing issue.  One method for selecting the front aperture/insert diameter is this.  

Based on your "wobble," you want to keep the target (black bull) visible COMPLETELY INSIDE the aperture most of the time.
What this means is when you start out you need a BIG aperture, and as your hold gets more steady you move to smaller apertures.
And on bad days when your wobble is larger than usual, just go back to a larger aperture.

The eye will naturally try to center the bull inside the aperture.

But, having said all this, there is such a thing as a TOO BIG aperture.  So if you are REALLY wobbly, (like me on a real bad day) you will have to accept that the bull will be outside the aperture for a larger amount of time.

The logic behind this method is that if the aperture is tight, the target will spend most of its time going outside the aperture.  And this will cause you jerk at the trigger when the target gets inside the aperture.  Using a larger aperture lets you concentrate on the sight picture and a gradual release, and not trying to jerk the trigger.

[Mick]

To make it "easier" to determine the optimum front aperture size for any standard target, and sighting radius, many years ago I expanded on the original theoretical analysis of Karas and came up with the chart I show in the Projects section of my website .....

http://fuzzylimey.net/projects/targapert.html

Although I would not recommend using an aperture smaller than the size indicated, it is sometimes beneficial to go up 1 ~ 2 sizes to offset the effects of weather, poor lighting - or a large wobble zone.

Mick - The Fuzzy Limey
http://fuzzylimey.net