How aperture sights work:
http://members.cox.net/smashbang/Aperture_Sight.htm
Just another argument for a rapid-fire cadence as far as I can figure. As Nickle famously says, "Don't fuss the shot."
Your average "Joe", watching Matt Damon or whomever blast away with an endless auto-loader in each hand, could never conceive the variables in actually using these tools properly.
Thanks FM. It's been a while since we worked together at Piru in 'O8. Cheers.
I'm confused. If the conclusions reached by the authors (if I understood what I read) are correct why isn't consistent cheek weld a non-issue? Why do you usually have to adjust the sights on a rifle when you use it if someone else sighted it in?
Did I misunderstand the point of the article?
From what I gathered, according to the article, consistent cheek-weld is important for a consistent response to recoil.
This may apply to adjusting sights as well. The ergonomics of the shot.
Shooting effectively is the art of managing many variables, cultivating consistencies in order to achieve a predictable, satisfactory outcome. The authors explain how the aperture sight is more forgiving in terms of sight picture error, more so than we may have intuited.
They're reporting the news, and this 'story' has good and bad elements.
Good: aperture sights, if used as the authors advise, are forgiving of inconsistent/eccentric eye placement with respect to 'centering' the eye in our familiar, preferred, symmetrical pumpkin-on-a-post sight picture. Note author's caveat to keep the pumpkin centered on the post sight, even if the pumpkin and post are biased to one side.
Bad: if you're inconsistent with cheek weld or other steady hold factors pertinent to the alignment of your eye with target and sights, you have probably also undermined the physical stability or shot to shot repeatability of your position. Consistency is especially important for field position shooters.
Quote from: Old Dog on May 08, 2010, 09:05:44 PM
I'm confused. If the conclusions reached by the authors (if I understood what I read) are correct why isn't consistent cheek weld a non-issue? Why do you usually have to adjust the sights on a rifle when you use it if someone else sighted it in?
Did I misunderstand the point of the article?
The article assumes a fixed rifle (vise, etc). Eye relief, chicken neck, cheek weld are all factors in accuracy (steady hold factors) as you aquire your NPOA and maintain it throughout the string of fire. As you cheek weld changes, so will your sight alignment. The front sight may still be on the target, but if you do not maintain a consistent sight alignment your point of impact will change. The point of impact exercise in the article mentions a different "hold" on the rifle as possibly effecting point of impact. Cheek weld, etc are part of the "hold".
The point of impact exercise is also misleading. The sight alignment must first be correct and then maintained before lifting your head and changing the
perceived sight alignment demonstrated in the exercise. I do not believe that the article was intending to dismiss sight alignment as essential to tight groups. I believe that it illustrates the fact that if you aquire and maintain your natural point of aim, you do not need to fuss the shot. Cheek weld is a critical part of this. The article illustrates that your perceived sight alignment may not be perfect but if you maintain NPOA your point of impact can be maintained. If you close your eyes, you have zero perceived sight alignment but if your NPOA is maintained, you can squeeze the trigger and have a well placed shot.
How I would illustrate NPOA and sight alignment differences is to get in position with a good NPOA, sight alignment and sight picture. Now move the buttstock slightly so that the rear sight moves. Now move your head so that the sight alignment appears correct. You will have a point of impact change yet have perceived sight alignment.
Good article. Could add to why a person needs to sight in their own rifle. Pupils are not perfectly round and everyones vary a little. Don't know how much a difference that would make though. And those long waits in prone. Waiting and waiting for that firing command to come. Could retinal burn in occur?