Wednesday, March 17, 2010

Old eyes, can't see, and rear apertures

 Old Eyes and Iron sights  --  Part 1
It gets harder and harder to get a good sight picture, and sight allignment these days. They say that old eyes lose resolving power, and suffer reduced depth of field as one approaches 60 years old.  Well, for me, that age milestone was passed years ago, and Iron sights are becoming a real problem -- and for some strange reason aperture sights are more a problem than battle sights (???).
   I shot two matches this past weekend.  Saturday I did very poorly in the Sm Bore Road Runner match -- lots of wild shots, off call.  I just couldn't see the target.  Sunday, I shot the Martin Cup 500 yd match and did quite well -- 4th, one pt out of 2nd, and I could see the target.  So, what was different?   Lunching with German Salazar, Mike and Tara Toliver after the match,  I mentioned that today I had been using a very small rear aperture(0.9) whereas on Sat. the light must have been different as I was using a very large rear aperture (1.5). Both German and Mike said right away the large Rear aperature I used on Sat was the cause of not being able get a good sight picture and the cause of the wild shots.
  I have been using larger rear apertures for years, and recently more so because I have been using a 30mm "Right Sight" on the front, and I like to have a good line of white around the front globe for the purposes of getting good sight alignment.  Yes, I use the front globe for sight alignment not just the aperature.  I have also thought that my real problem with "wild" shots was sight alignment and not sight picture, NPA, position, etc.
   German, being the good mentor that he is, once again advised me to forget the front globe, and the concept of sight alignment, and just concentrate on the front aperture and centering the bullseye.  He says to just "look through" the Rear ap, and forget about it.  "If you close the Rear Aperture down to where you can barely see anything, then open it up just a little and simply look through it, you will not have sight alignment problems.  If the rear aperture is really small, your eye must be centered to even see through it.  The small aperture will increase your depth of field, the front sight and the bull will be much sharper and sight alignment will become automatic.  On a small bore rifle--snuggle right up to the rear sight and close that aperture down to even 0.7 and just "look through it and forget it".
  Well, I'm ready to try anything to help my sagging scores, so I went out yesterday to the range and tried the very small rear aperture, and yes I could see much more clearly and I seemed to have no alignment problems.  The first 3 shots went in the same hole! The rest of the target went very well, and I am now ready for the first day of the Western Wildcat matches starting tomorrow.

Result: 10 shots- 50m UIT target -- Iron sights --yesterday SK std ammo
  We'll see how it goes.
Hawkeye

1 comment:

German Salazar said...

Jim, I think you've got the idea down perfectly! Center the bull in the front aperture, forget the rest and break the shot before vision deteriorates and wind changes. A well centered, reasonably sharp sight picture with quick shot execution is the objective.

We may not be in our 20's anymore, but that doesn't mean we can't shoot good scores with irons, only that the techniques change. Well done!