Why there is a difference in alignment among different shoot

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TCK

Why there is a difference in alignment among different shoot

Post by TCK »

I have a question bordering me for some time and cannot find a justified explaination.
The rule of geometry tells us that to form a stright line, at least you have to have two co-ordinates, and once there is a straight line, all points on that line are totally aligned.
The question is when we aim at the sight, 4 points, the aiming eye, the back sight, front sight and the impact point on the target should be on a straight line. The last 3 factors should be quite constant and only the aiming eye is a variable. The fact is each individual handgun (AP or normal pistol) will have a different point of impact on different shooters' hands. I can hardly explain why this would happen as on what I believe, a shooter will put his eye on to the imaginery line formed by the back and front sight and the target. The point of imapct should not be that significant.
I know some may point out that trigger action will make such difference but I notice that even bench resting shooting have the same phenomena.
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hmmm...

Re: Why there is a difference in alignment among different s

Post by hmmm... »

What you're overlooking is that, with adjustable sights, the rear sight, front sight, and impact point are most decidedly NOT in a straight line.

: I have a question bordering me for some time and cannot find a justified explaination.
: The rule of geometry tells us that to form a stright line, at least you have to have two co-ordinates, and once there is a straight line, all points on that line are totally aligned.
: The question is when we aim at the sight, 4 points, the aiming eye, the back sight, front sight and the impact point on the target should be on a straight line. The last 3 factors should be quite constant and only the aiming eye is a variable. The fact is each individual handgun (AP or normal pistol) will have a different point of impact on different shooters' hands. I can hardly explain why this would happen as on what I believe, a shooter will put his eye on to the imaginery line formed by the back and front sight and the target. The point of imapct should not be that significant.
: I know some may point out that trigger action will make such difference but I notice that even bench resting shooting have the same phenomena.

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Mark

Re: Why there is a difference in alignment among different s

Post by Mark »

This a total guess with no research to back it up, but I'm guessing that the "misalignment" that results in each person having small differences in sight settings occurs with how each person "sees" the sights. Perhaps subtle differences in what angle each individual views the sights or perhaps even what part of the retina the image of the aligned sights strikes. But I'm just guessing.
: I have a question bordering me for some time and cannot find a justified explaination.
: The rule of geometry tells us that to form a stright line, at least you have to have two co-ordinates, and once there is a straight line, all points on that line are totally aligned.
: The question is when we aim at the sight, 4 points, the aiming eye, the back sight, front sight and the impact point on the target should be on a straight line. The last 3 factors should be quite constant and only the aiming eye is a variable. The fact is each individual handgun (AP or normal pistol) will have a different point of impact on different shooters' hands. I can hardly explain why this would happen as on what I believe, a shooter will put his eye on to the imaginery line formed by the back and front sight and the target. The point of imapct should not be that significant.
: I know some may point out that trigger action will make such difference but I notice that even bench resting shooting have the same phenomena.

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Ken J

Re: Why there is a difference in alignment among different s

Post by Ken J »

Well, well, well,
It all has to do with the dynamic response of the gun in question. Hold a pistol loosely and you will have a different point of impact than when you hold it tightly. Same for rifle. Sight allignment is also a big one. Most folks think you merely line up the sights on the target and yank on the hangy down thing. Truth is, job number one of a shooter is to line up the sights NOT with the target, but with your eye. You must have perfect sight allignment. If not, it's just like clicking your sights. Try it. Have perfect sight picture on target, but misalign your sights. You'll have the same affect as clicking your sights.
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akihmsa

Ken understands perfectly, but few will understand.

Post by akihmsa »

What happens after the trigger has been released but while the projectile is still within the gun is the answer. As Ken pointed out everything from how the gun is gripped to the mass of the shooters body etc. etc. has an effect. Even bench rest rifles are in dynamic motion.
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Jack H

Re: Ken understands perfectly, but few will understand.

Post by Jack H »

A perfect example of these frustrations:
I fired two five shot strings 50 yards armrested from a S&W 41 that is very accurate. There were two separate 1/2" groups about 3/4" apart. The only difference was stopping to reload and no doubt a grip change.

: What happens after the trigger has been released but while the projectile is still within the gun is the answer. As Ken pointed out everything from how the gun is gripped to the mass of the shooters body etc. etc. has an effect. Even bench rest rifles are in dynamic motion.

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Mark

Re: Ken understands perfectly, but few will understand.

Post by Mark »

I thought the question was why everyone has their sights set differently. Are you guys saying that we all have our sights set differently because we all have different, but ultimately freakishly CONSISTENT, yet undiscernable movements while the projectile is still in the barrel???
: A perfect example of these frustrations:
: I fired two five shot strings 50 yards armrested from a S&W 41 that is very accurate. There were two separate 1/2" groups about 3/4" apart. The only difference was stopping to reload and no doubt a grip change.
:
: : What happens after the trigger has been released but while the projectile is still within the gun is the answer. As Ken pointed out everything from how the gun is gripped to the mass of the shooters body etc. etc. has an effect. Even bench rest rifles are in dynamic motion.

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Dan

Re: Ken understands perfectly, but few will understand.

Post by Dan »

: I thought the question was why everyone has their sights set differently. Are you guys saying that we all have our sights set differently because we all have different, but ultimately freakishly CONSISTENT, yet undiscernable movements while the projectile is still in the barrel???
That sounds about right to me. That's why co-ordinating the shot release with your heartbeat (unconsciously or otherwise) is so useful.

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Matt E.

Re: Why there is a difference in alignment among different s

Post by Matt E. »

Ken's points are quite true, but I believe part of it also has to do with a person's eye. I'm not sure the biological reasons are, but simple fact is: different people may see different things. For example, I can shoot one of my teammate's guns and hit say, low and to the right while this person is centered. I can come back a different day and do the same thing, and hit the same place. This comes from a good shooter shooting another good shooter's gun, so we are centering the sights up. Part of it could be head position, but it could also be some sort of perception difference. I have no scientific data, but this is what I've come across in experience.
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Mark

freakishly CONSISTENT, yet undiscernable movements

Post by Mark »

I dunno. That seems a lot to swallow. It seems improbable (to me) that I might consistently twitch 0.002 seconds after pulling the trigger exactly 0.003 inches up and 0.005 inches to the left, with enough consistency that my sights could be adjusted to compensate.
It just seems more logical to me that the difference might be because of the way each individual's eye's receptors (those cone and rod thingies) perceive the sights.
Anyone with a background in neurology or opthamology got any ideas?
: : I thought the question was why everyone has their sights set differently. Are you guys saying that we all have our sights set differently because we all have different, but ultimately freakishly CONSISTENT, yet undiscernable movements while the projectile is still in the barrel???
: That sounds about right to me. That's why co-ordinating the shot release with your heartbeat (unconsciously or otherwise) is so useful.

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Dan

Re: freakishly CONSISTENT, yet undiscernable movements

Post by Dan »

: I dunno. That seems a lot to swallow. It seems improbable (to me) that I might consistently twitch 0.002 seconds after pulling the trigger exactly 0.003 inches up and 0.005 inches to the left, with enough consistency that my sights could be adjusted to compensate.
No, it's not that you twitch consistently; it's that the involuntary springiness of your shoulder as the recoil pushes it back will be different from the springiness of my shoulder, so that the movement of your muzzle (while the bullet is moving down the barrel) will be different from the movement of my muzzle. Therefore the impact point (if our sights are set identically) will be different.
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TCK

Perhaps my poor English has confuse all of you.

Post by TCK »

It is interesting that my question has resulted in so many replies. Some ideas have never been coming up to my mind.
However, I believe Matt E get the exact situation and of what I really want to understand.
What really amuse me is sometimes we exchange our tools for shooting, either it be AP, FP or others among members, take for granted that the piece has been zeroed by its owner. However, we consistantly shoot groupings that are far away from the original point of impact, or as Matt E. mentioned, in different days, sessions so that it become a norm that if we borrowed a piece of equipment to shoot, we roughly knows how many clicks we have to adjust in order to bring the impact point back to the centre.
We understand that among different shooters, their point of aim is different, some have sub -six hold while others mya not, but taking all these factors into account, the difference in the groupings are far beyond these factors effects. Say I can have a dead centre with my GSP ,22LR with a sub six hold while understand this fact, my friend shoot his groupings all to the 5th ring at 11 o'clock. If he adjust the sight so that he can shooside the 9/10 ring, I will shoot them all to the 6/7 ring at 5 o'clock. This is rally funny to me because when I let others to shoot my pistols, most will shoot onto the upper left and when I shoot others', mostly it will be on the lower right of the target.
Even I try other's AR, which can easily shoot a one hole grouping and the sight picture is quite consistant by lining the 3 circles into coaxial, I will ususlly shoot 9's instead of 10 at the 1 o'click area.
After knowing more about my case more, can anyone have their inputs. This is a question as to many combat type psitols with fix sights, how can they shoot with precision under different hands. I know one very interesting thing about the local police is they do not operate their own equipment, for the normal PCs, they returned their pistols to the armory after each duty and collect a pistol when they return for duty. This means they are using probably a different pistol every day.
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Mako

Re: Perhaps my poor English has confuse all of you.

Post by Mako »

With general police side arms it makes absolutely no difference ... you cannot regard their shooting to be anywhere near precise! :-(
The few law enforcement officiers that I know that do shoot competatively ... lament the lack of interest and practice their fellow officiers ... on whose "expertise" their life might depend on ... put into their shooting.
I believe that a lot of the difference in point of impact comes from hold. It also shows how important a consistent hold is ... and why it's important to have a well fitting grip. It's also perhaps the reason that shooters using pistols with "straight" standarized grips like on the basic 1911 MUST use very tight grip strength ... to get tight groups ...
makofoto-at-earthlink.net.46030.45981
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