can Cooper be right about aperture sights?

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roscoe

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In my copy of the Art of the Rifle (P.58) Cooper says two things about aperture sights that I find odd.

1. That the front sight need not be centered in the aperture. How can this be right? The aim of the barrel on the rifle must be different when the front sight is one one side, relative to when it is on the other side. And a related issue:

2. The size of the aperture does not make any difference. I have been wondering about this. My Winchester 1894 has an XO ghost ring, and it seemed to me that I would be more precise at distance with a smaller aperture. I was thinking of how nice it would be to have an AR-15 style set-up with two sizes of holes available. I can't imagine that it really makes no difference.


He mentions that many people cannot understand this, and you can count me as one of those.
 
Haven't read the book, but must agree with your observations, roscoe.

Sigh alignment is more important than sight picture in precision, long range shooting as the error is multiplied as the range increases with mis=aligned sights. I prefer a smaller aperature (one small enough to sharpen the front sight) to a larger one, but that is my personal preference.

The eye tends to automatically center the front sight in the rear aperature (whether large or small) and this may be what the author alludes to?? If the target is close enough and large enough, guess sight alignment is not so important. :)

You would be surprised at how small a group you can shoot @ 100 yards without a rear sight on your rifle. Have done this, using precise spot weld on the stock, and shot quite small groups with rear sight removed completely.

Having said that, still prefer a smaller rear aperature to a larger one for
precise shooting and sight alignment is important, IMHO.

Regards,
hps
 
I would imagine that the size of the rear sight aperture having NO effect on how accurately the rifle can be fired will come as a surprise to many Highpower competitors.
Cooper is a goldmine of experience but frequently relates personal opinion as fact applicable to all.
If he would see fit to throw in an occasional "in my opinion" or "my personal experience has been" it would be refreshing.
 
Let me truncate your question to a form I can answer:

Can Cooper be right?

Often times, no. Sorry cooperphiles, I think the man is too apt to step right off the common sense trolley, but trumpets his opinions boldly - as to appear to have some weight.

Maybe in his mind, relating to a very specific reasoning, his statements make sense but I find that taken at face value alot of his advice smells like the business end of a horse.
 
I hate to try to judge from just one sentence out of a paragraph. It's too easy to get out of context and not get the exact meaning...

The only aperture sight I've used in many a decade is that on my old Schutzen rifle. The hole is tiny, to say the least. It's quite precise, but very slow. From what I read, the ghost ring style is quite rapid at target acquisition, and is sorta instant hunting accuracy.

I don't doubt you can get good target accuracy with a ghost ring, but the smaller the aperture, the more precisely you can center the front sight. You can "good-eye" the center of a 6" stick more accurately than you can with a four-foot length...

Art
 
As some of you have noted, Cooper is often quoted out of context; however, on reading Cooper myself, I often note he throws out a seemingly authoritative statement without providing any context so it is impossible to tell if he is right or wrong as the only context is in his mind - i.e., what was he thinking?

For the benefit of Cooperphiles I have bastardized or adapted the term ex cathedra to include Cooper's inscrutable pronouncements.

Latin: "from the chair" (throne), as in a statement proclaimed by the Pope is deemed by Roman Catholics to be infallible if given ex cathedra. ;)

If you want to read more about this definition, go here: ex cathedra
 
As Art says, it is easy to take the comment out of context. Looking at the comment alone, you're right, it doesn't make sense.

It is true that you may not need to have your front sight in the center of the rear aperture, but for best accuracy, you need to have the front sight in the SAME PLACE in the rear eachand every time. It just so happens that it is most easily alinged in the center of the rear.

Yes, I am surprised to hear that the size of the rear aperture doesn't make a difference. When I shoot a stock Garand or (worse) a 0-200M AR aperture, I feel like I can walk through it! Way too much slop for precise shooting.
 
I can understand the rear sight size making no difference IF: you can somehow put your front sight at the EXACT place every single time. I think that smaller sights allow you to adjust your weld so that the front post is centered. Harder to tell if your using a large rear ring.

FWIW.:rolleyes:
 
The literature I'm familiar with indicates that the aperature has to be below a certain critical size in order for the eye to automatically center the front sight in it. In my experience, when the aperature is below this level (i.e., pretty small), the bullet hits where the front sight is, so I would agree in this case that the front sight need not be centered. If the front sight is slightly right, the barrel is too, so I don't see the problem.

Jaywalker
 
I'm going to buck the trend here and say that I think he's right on both counts - if he was thinking but didn't say, "... as long as it looks fairly centered to the eye." The human eye/brain system is pretty damn good at getting things aligned automatically. No practical person is going to fire for accuracy when the front post is off to the side of the aperture. I just tried with a Win 94 (handiest rifle with a peep on it). The sight picture is so wrong you would have a natural tendency to correct it so that it is more centered.

The second premise, that the size of the aperature doesn't matter, falls into the same thinking as above. But there is a practical limit to the statement. It certainly wouldn't be true if you Krazy glue a tin can with both ends cut out on top of your rifle. But for most available aperture sights meant for rifles, I think the eye/brain centering effect would still hold.

Now, if he meant precisely what was written, then Sam is spot on - 'wrong', and 'it depends'.
 
I'm sure that Cooper was talking about combat shooting or hunting and that the quote was taken out of contect. I don't think Cooper has EVER written about any sort of target shooting - all of his stuff is on "real world" shooting.
You don't need a tiny aperture to shoot a deer (or a man) through the ribs at a couple hundred yards.

Keith
 
I think that smaller sights allow you to adjust your weld so that the front post is centered. Harder to tell if your using a large rear ring.
Click to expand...

Shai,

If you are trying to center the front sight, then you don't how to use an aperture sight!
They only work well if you completely ignore the rear sight - the idea is to look THROUGH the sight! If you are trying to use the rear sight as a reference in the same way you'd use a traditional sight, then you might as well stick with a buckhorn or something and be done with it.

The only advantage to a ring sight is that it removes one focal plane that your eye and (conscious) brain has to keep track of. When you align the sights of a rifle with a traditional sight, your focus is actually jumping back and forth from rear sight to front sight to target. And your brain is trying to keep these three objects in alignment.
With a ring sight (used correctly) you simply focus on the front sight and align that with the target. And through some accident of optics, your brain will automatically keep that front sight centered within the rear ring. I can't explain that, but it's simply a fact.

Aperture sights (even very large aperture sights) are faster and more accurate than traditional sights WHEN USED CORRECTLY.

Keith
 
Like you say, you look through the rear sight.

This is how the process works for me (and I'm just about as far from an expert as you can be). I get my cheek wield, adjust head position, compare rear sight to front sight, make any head adjustments necessary to center front post, focus on front sight and target.

It sounds long and drawn out, but it only takes a second or less. I mostly have to look at the rear sight when I'm in a position that shifts the rifle angle around, like from offhand to prone to kneeling or what not.

Once I get that post where I want it, then I can forget about the rear sight.
 
If you are trying to center the front sight, then you don't how to use an aperture sight!
Click to expand...

The eye will automatically center the front post in the rear aperature, even larger onesup to a point resulting in hits if target is close enough and large enough. :)

For long range, precision shooting, however, the shooter had better be sure the post is in the precise center of the aperature. This becomes more and more difficult as the size of the rear aperature increases. Ghost rings (or even eliminating the rear sight altogether, if the rifle fits the shooter) can be quite accurate and extremely fast at short range.

The only advantage to a ring sight is that it removes one focal plane that your eye and (conscious) brain has to keep track of.
Click to expand...

Absolutely, but there is one other extremely important advantage of the aperature sight (especially for older eyes:( ) in that, by choosing the proper size opening in the aperature for the shooter's eyes (and this varies also depending upon available light) one can "sharpen" up the front sight (actually see the blooming thing, even w/67 year old eyes).

Perhaps what Cooper was saying was, as Steve pointed out, that post need not be centered....., he (Cooper) just failed to complete the statement:

It is true that you may not need to have your front sight in the center of the rear aperture, but for best accuracy, you need to have the front sight in the SAME PLACE in the rear eachand every time. It just so happens that it is most easily alinged in the center of the rear.
Click to expand...

Regards,
hps

Edited to read: he (Cooper)
 
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Here's how I see it....


Sure, a person can manage to be just as accurate on target while using a large aperature sight when compared to firing an equally capable firearm only with a small aperature sight. After all, "centered" is still centered no matter if it's large hole or small hole.


Like everyone else has pointed out, it boils down to a level of precision and most of us will all agree that small aperature sights can be more precise. Or rather, the sight forces the shooter to bend to the rather low amounts for error allowed by the sight's very design.


But it strikes me as somewhat funny, this whole thing is somewhat similar to the general misconception by some folk that longer barrels mean "more accuracy" and that shorter barrels mean "less accuracy". The firearm/barrel length plays little in terms of accuracy potential but the real culprit often over looked is the sight radius of the firearm and the fact that firearms with shorter sight radius allow for less precision than firearms with longer sight radius. It just so happens that the shorter barreled guns are often the ones with the shorter sight radius, while less precise they usually aren't less accurate.



Long story short, there are times when precision can be sacrificed or there are shooters who can wring the most performance despite the system not being tuned for utmost precision. Generally though, everyone is interested in maintaining as much precision as possible, or the marksmen are atleast.
 
Well, yeah... all things being equal, you can be more precise with a smaller ring than a larger one, but the concept doesn't change. You still should look through the site rather than attempt to consciously center the front post.

And again, all things being equal - The size of that front post is far more important for precision than the size of the rear ring.

As an example; I have a stock 10/22 where I've replaced the Ruger buckhorns with an inexpensive aperture type sight. I stuck a post type front sight on it and got pretty good accuracy - better than with the stock sights, anyway. The rear sight had various sized replacement apertures and I fiddled around with different sizes and didn't see any great improvement between one and another.
Yet, that post was so broad that I knew I could do better. I filed down the front sight so that it was effectively a sharp point and was really amazed at the accuracy I could get like that. I wouldn't have thought such groups were possible from a stock 10/22!
Of course, I could only wring that accuracy out in perfect light conditions because the post was too darned thin. The rifle was now useless for rabbit hunting, so I replaced it with a "Firesight".
It was good lesson in the basics of aperture sights. And I realize that monkeying around with a 10/22 is a far cry from long distance shooting with a "real" rifle. Still, it was educational and I learned a lot!

Keith
 
Leaving the second statement alone, I wonder if the centering thing is actually a statement of optical fact:

Aperature sights do some things that are similar to a pin hole camera. In other words, that small hole has light bending optical properties. I wonder if that lens like effect actually keeps the front sight centered (actually distending the image toward the edges of the rear), even if the image of the front sight appears to be off. To put it another way, if you can see the front sight through the aperature, maybe it is centered on the target behind it, no matter how it appears in the sight.

Of course, it should be easy enough to try out. One just needs to be sure that you are always keeping that front sight centered on the target as you try and shift around your view of it.
 
Pick up an object with a round hole in it - a washer or something like that. Hold it a few inches from your eye and look through it at something across the room - the knob on your tv...

Don't try and center it, just look THROUGH the hole at the selected object. You'll discover a couple of interesting things:

First: You'll see that the object is centered. It will wave around some because you don't have a stock weld, etc, but it will be roughly centered.

Second: (and to me, more interesting) is that if you move your head slightly so that the object is no longer centered - your fingers will automatically move the ring so that it becomes centered again. You can "will" this not to happen and leave it off-center, but if you just let nature take its course it will happen without any conscious action on your part.

When you consciously attempt to center the object you are trying to overcome something that will happen automatically - and happen just as well - and probably quicker... Why mess with a good thing? Just let the unconscious part of your brain deal with that while you concentrate on that front sight.


Keith
 
Having put a lot of rounds downrange through both aperature rear/post front and aperature front and rear sights, it has been my experience that the shot goes astray in the same direction and to the extent that the front (post or aperature) is off center in the rear aperature. Any error in sight alignment is multiplied as the range increases. A sight alignment error of approximately .007" equals one minute of angle (depending upon sight radius) or 1" for every 100 yards.

I will qualify that statement, if deference to Steve's correct observations, by sating that an error in sight alignment, not necessarily off center; my rifles have always been sighted in for a sight picture using a centered front sight.

Regards,
hps
 
I did not mean to insinuate that I use a less-than-centered sight alignment technique, I was merely stating that the sights are "always aligned on something" and it is the shooter that must find a way to center himeslf behind the sights properly, and consistently. If one were to *incorrectly* but consistently align the sights, he could adjust the elevation and windage to cmpensate for the improper alignment. Not the best method, but it would work.

HPS1, you are 100% correct that any sight misalignment is magnified exponentially at distance. Knowledge of this would have to be applied to the above paragraph. An "incorrect" yet consistent sight alignment, coupled with an adjusted sight position to accomodate for said misalignment, would only be correct for one particular distance. Similar to a firing solution for ships from land based gunnery.

Further, one must wonder about those shooters who ALWAYS need "3 clcks left at 300" and "5 clicks right at 600" on the same gun for a no-wind zero. Don't tell me that the gun magically changes its POI when you change yardages. No. The shooter is not achieving the same alignment with the sights, in different positions, or in a tighter hold. Therefore, he accomodates for it by adjusting his "no wind zero" for each yardline. I suppose that is a compliment to me, as I have no clicks left or right for my no wind and any yard line.

As an aside:
There is a phenomenon now named the Toer Spot (after a Dr. Toer I'm told) that occurs when one looks through an aperture. When your eye is directly behind the aperture, the Toer Spot appears. One may see it easiest when looking at the sky through the aperture. Once you have seen it, you can see it no matter what the background. I check to see if there is a Toer Spot before each shot at the 600 yard range. I average a High Master score at the 600 yard range, and I think the Toer Spot helps.

HPS1, I also agree that the front sight is not naturally centered for great distance and high precision shooting. One must make a point to center the front sight in the rear.
 
Steve:
Thanks for the info on the Toer spot.....never knew that little rascal had a name before:D . First time I ever noticed it was when I had my Merit disc closed down a little too much and it became quite obvious. I use it to determing correct aperature size.

When I first started shooting highpower in the service (just after they went to breech loaders;) :D ), it was verboten to cant the rifle! Now, it is considered good form (and I agree 100%) to cant the rifle so that the sight is directly in front of the center of the shooter's eye. This is especially helpful to shooters who require corrective lenses so that the sights and target are in the center of the corrective lense. Steve, don't you think a lot of the windage difference problem you outlined from one yard line to the next could be caused by an inconsistent cant on the rifle from one yard line/position to the next?

Regards,
hps
 
That could be as well. With a rifle such as an AR-15 A2 or a Match Rifle with a very high sight plane (Texas Tall Boy sights) a cant will exacerbate the windage/elevation:cant vector. You know as well as I do, when one cants, one may need to put windage on for elevation, or vice versa. I know that Mr. Tubb cants one way for sitting and another for prone, and sets his rifle up for the prone cant. That proves that one can have the cant wrong, but if your eye is in direct alignment with the sights, you will not have a problem. Cant is often more of a comfort issue than a sight alignment issue. I try to avoid cant at this time, with exception to standing, mainly because it is an extra variable that I don't feel that I can control at this point. Besides, it is difficult to know when you are canting exactly the same way when shooting a Service Rifle. A Match Rifle can have one of those handy little spirit levels on the front sight. I have found that I can see a Toer Spot at all distances with no cant (except for standing), if I do my part.
 
Cooper is mostly right here.

I shoot a lot of CMP and just general plinking with my aperture sight sighted rifle. The way I shoot it is with the ears of the front post touching the top of the aperture and the top of the front sight right where I want the bullet to go. In this way, the front sight is actually high of center and the rear sight could reasonably be any diameter the user wished although different apertures would necessitate a sight adjustment for elevation. With a narrow, match aperture you lose a lot of light which makes shooting in less than perfect lighting nearly impossible, but it does give you a larger depth of field which can help those with less than perfect eyesight.

I hear lots of people say how your eye naturally centers the front post. I guess it depends on how perfectly centered you want the post to be. Unless I make a determined effort to be sure my sights are just perfect within the rear sight, I'm lucky to get a 5-inch group at 100 yards.
 
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