3X9 and accuracy

Stephen Perry and all,
I should specify, the rifle in my hypothetical situation is a Remington 700 BDL 222 and is very accurate for a factory rifle (solid .3s). No wind, solid front rest and rear bag, 100 yards. Not how accurately can I shoot this situation with a 3X9, but instead, realistically how accurately can this be shot with a 3X9 as compared to a higher powered scope, like a 24x. So essentially the rifle is accurate, no wind or mirage, the only variable is scope power.
Thanks.
Matt.
 
I don't agree with the man who stated you have to forget your 9X and find yourself a 24X.

The magnification is the apparent size, but the RESOLUTION depends on the size of the objective lens.

A fat 9X scope may have an objective of 50 or 60 mm, and be the equal of an 18X in resolution.

Resolution is the overall clarity, such as the ability to see bullet holes. Magnification is just the apparent size.

I have a large-objective Leopold on a rifle at 7.5X fixed power. I see the bullet holes at 100 and I have no difficulty with my hold with the goal of sub-minute groups.

Agreed, you will want to choose your paper target pattern carefully to suit your particular scope.

The problem with this forum is -- when you read the messages -- the fellows without a clue, who are just ignorant, blat out their message with complete assurance. The fellows who actually know what they are talking about-- their viewpoint is just diluted by all this ignorance.

I suppose I am going to get people mad, but I read some excellent advice here -- and some real bonehead drivel too. The only thing I have got going -- I have some idea which is which. I feel sorry for the newbies who are struggling, and don't have the experience to sort out the nonsense as opposed to the wise, experienced advice.
 
Objective size has nothing to do with resolution....simple fact. Quality of lens and coatings are what determine the resolution.

Hovis
 
What HovisKM said +1.

Go get a Leuy 4x40 and look thru it and then get some $29.95 15x60 tacti-cool scope and see the difference.;)
 
Definitions of terms

It would appear that some of the disagreement between posters is based more on differences in their interpretation of the meaning terms used.

Resolution = the ability of a telescopic sight to reveal an angular separation of fine details.

The greater the aperture of a telescope, the more detail it will reveal. The theoretical angular resolution is Dawes's resolution limit [MOA] = 1.933 / Objective Diameter [mm].

Match magnification means the Dawes Limit equals the magnified normal visual acuity of the human eye (1MOA). At less magnification the resolution is limited by the user's eye. Above this magnification the resolution is diffraction limited by the objective diameter to the Dawes Resolution Limit (MOA) above.

Resolution Limit = Smallest separation between features and minimum POA (point of aim) error (confusion circle)!

NOTE – while it is possible to find telescopic sights of such poor quality of lenses and lens coatings that this limits the resolution to less than the limit imposed by the objective diameter, any telescopic sight likely to be even considered by the readers would be of sufficient optical quality to have resolution diffraction limited by the objective diameter.

Accuracy = offset from point of aim – of point of impact for single shot – of center of group for a group of shots

Precision = dispersion of shots within a group – typically the center to center distance of the two most widely spaced points of impact of shots in the group
 
For testing/developing loads I use all the magnification I can without compromising clarity.
My home range is very dark even when the sun is blazing.

I find it quite beneficial to know exactly which shot was the spoiler. In conjunction with a chronograph this gives great information for tweaking.

Also, For instance say I'm testing 5 shot groups. I'll pay more attention to the last four or even three shots as opposed to all five. Was it settling down at that powder charge or did it start tight and begin to open up? Very important information concerning bore condition in my opinion. But thats a whole nother can of worms.

If I can not see every hit on the paper I feel blind, stupid and full of questions.
I'd prefer to just feel stupid.
 
A higher powered scope may let you see your large group better but it won't make it any smaller :D

I've got a 1.5X5 Leupold which will easily resolve 6MM bullet holes at 200yds, at 5X.

al
 
alinwa

I did say my personal range is dark. My buddy has been playing with a M-14 with a Springfield Armory 6X on it. A fairly decent scope clarity wise.
He cannot see .30 holes at 100yds.

Most of that is his fault though. He insists on using brown paper bags with white paper squares for aiming points. He also doesn't bother using my chrono which is always on the range ready to set up.
He's content to walk 100yds and see what he did then wonder why one or two are out of the group of seven. To each thier own.

If he's the one who told you I shoot large groups just shrug it off and smile.:D
 
Well there you have it al. Now I feel stupid again and I'm not even sitting at the bench:D
 
Well Jo,

That's the nature of this game ....... about the time ya' start thinkin' y'er SMART someone slaps ya' upside the gob wit' a fish.

gottaluvvit!

al
 
Yep I agree. To my intellectual credit I eat all those fish so's I's have mo cash for boolits:)
 
Al,

That Leupold 1.5-5x20 is a good illustration of my physics of optics post. The 20 mm objective clear aperture diameter yields a Dawes Resolution (diffraction) limit of 0.097 MOA which would allow for 6 mm bullet holes to be resolved out to 240 yards with good seeing conditions. However, the maximum magnification of 4.5x (per Leupold specs) limits the resolution to 0.222 MOA for a user with normal (20/20) 1 MOA visual acuity [1 MOA/4.5 = 0.222 MOA] which then limits resolution of 6 mm bullet holes to 105 yards for that user.

The match magnification is 10.3x for 0.097 MOA. Therefore that scope design forces the resolution attainable to be limited by the observer’s visual acuity.

From your observation that “I've got a 1.5X5 Leupold which will easily resolve 6MM bullet holes at 200yds, at 5X.” we must assume that you have much better than normal, 1 MOA or 20/20, visual acuity and at least 0.522 MOA or 20/12.

To match your observation, persons of normal visual acuity would need 8.6 x magnification - like the 3-9x scope mentioned in the original question.

Al – thank you for that helpful post and congratulations on you superior visual acuity. Old shooters like me are envious since we struggle to get corrected to normal visual acuity.
 
Right on Fred....

So, a question for you.

Why do I often have to screw my optic bell clear down to the bottom of the threads to get my crosshairs to clear up?


BTW, I lied a little ;) The range where I last used the little Leupold was 186 measured yards, not quite 200. It was pretty funny though, me spotting bullets for the guy next to me using his big ol' Cheaper than Dirt "Sniper Scope" :)
 
The typical ocular assembly (eyepiece) on most scopes provides a corrective range of 3 diopters (-2 to +1 diopter typically) which is adequate for most users. However, for those with visual acuity that is either beter (20/10) or worse (20/40), sharp focus on the reticle may occur at the extreme travel limits of the ocular or even not be atainable.
 
I was talking to my gunsmith last night on the phone and I mentioned this thread. I asked him how many 3x9's, 6x's or any such scope what at the IBS Nationals 100/200yd. It's go me wondering....I never got an answer....he laughed so hard for so long that I had to hang up when my wife called supper for the third time and I was going to eat cold food if I didn't come. Maybe there was a bunch and he was laughing at me because I'm out of the loop????

Hovis
 
This is kinf of rediculous

The original post asked how accurately you can sight in an accurate rifle with a 3x9 scope on it. If you have a decent scope, you can sight in as accurate as the gun is!

A lot of blunder buss has arisen out of this post and I won't attack any of it. All I will say is a good rifleman with a 3x9 can shoot an accurate rifle very accurately.

No scope has ever made a poor rifle a better one, that just won't happen, but the question got taken over by another tangent. Yes, a higher power scope will let you see more of the target and can allow some to shoot tighter groups. It still won't make the rifle any more accurate no matter how great the optics are and a better rifleman can and will shoot better groups with the lower powered scope than some no matter how much better of a scope they use.

Now, attack that some more please!!:D
 
muslmutt said:
Stephen Perry and all,
I should specify, the rifle in my hypothetical situation is a Remington 700 BDL 222 and is very accurate for a factory rifle (solid .3s). No wind, solid front rest and rear bag, 100 yards. Not how accurately can I shoot this situation with a 3X9, but instead, realistically how accurately can this be shot with a 3X9 as compared to a higher powered scope, like a 24x. So essentially the rifle is accurate, no wind or mirage, the only variable is scope power.
Thanks.
Matt.
Click to expand...

I believe if a rifle can shoot solid .3's....a higher power scope with good lens and good clarity and POI will make a difference in the agg/load development.

Hovis
 
I’ll try to more directly answer the original query by Matt (muslmutt) as I understand his question. First let us simplify the problem by assuming the following hypothetical conditions:

1. Magic rifle and scope is perfectly aligned – mechanically
2. Ammunition is perfectly consistent – 0.000 group size
3. Shooting will be in a test tunnel – no wind and no mirage
4. Shooting will be from rests but must be placed and aimed

For reference we will arbitrarily select two scopes: Leupold VX-ll 3-9x40 and Leupold VX-ll 3-9x50. The actual specifications (from Leupold website) are:

1. Leupold VX-ll 3-9x40 is 3.3-8.6x and 41mm clear objective aperture
2. Leupold VX-ll 3-9x50 is 3.3-8.6x and 51mm clear objective aperture

From this we can calculate applicable parameters for each:

1. Dawes Limit of resolution = 0.047 MOA; Effective resolution [due to 8.6x maximum] for user with normal 20/20 (1 MOA) visual acuity = 0.116; Magnification to match normal user to Dawes limit = 21.2x
2. Dawes Limit of resolution = 0.038 MOA; Effective resolution [due to 8.6x maximum] for user with normal 20/20 (1 MOA) visual acuity = 0.116; Magnification to match normal user to Dawes limit = 26.4x

From these we can conclude that both designs are resolution limited by the 8.6x maximum magnification to the user’s visual acuity which for our normal user is 0.116 MOA. Therefore if our normal user were to set and aim this magic rifle each shot the actual POA (point of aim) and POI (point of impact) would be within 0.116 MOA of the target center. The error circle would 0.232 MOA diameter about the target center.

Back to the original question – the accuracy limit for a single shot would be less than 0.116 MOA and the precision limit for a group of shots would be less than 0.232 MOA for a normal user using either scope on the magic rifle. If you had 20x available, then – the accuracy limit for a single shot would be less than 0.050 MOA and the precision limit for a group of shots would be less than 0.100 MOA for a normal user on the magic rifle.
 
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