Curious whether any have compared group sizes of same rifle/loads using lower power vs. higher power scopes: and if so, how much of a jump in power to see a difference. For example, lets say you are using a 2-7x and shooting set at 7x. Any gains in accuracy by going up to say 12x? Or does it take MUCH higher, say 20x to see a difference. thanks

When developing loads I am generally testing accuracy at 100, 200, 250, 300 and 400 yds. With the scopes I use my habit is shoot on 4X closer than 200 yds and further than that all shots on 12X. Some of my scopes will dial 18X but for hunting I record longer range bullet drop on 12X only.
I am roughly trying to duplicate actual field use of the optics and this generally allows me to find the load's accuracy potential, or lack of. My targets are luminous squares. Up to 200 yds size is 50 x 50mm. At 300 yds 75 x 75 mm. Beyond 300 yds either 100 x 100mm or 150 x 150 mm.
Up to 200 yds I can hold steady enough for little enough group size difference it doesn't matter for hunting, whether on 4X or 12X. Target acquisition is much faster on 4X.
Past 200 yds on 4X I can't discern scope wobble and groups tend to be more open. But on 12X due to more discernable scope wobble I tend to take the time to become steadier and consequently get a better shot away. Also, with this much magnification I see much better exactly where the crosshair is holding on the target.
I have tried the longer shots with the scopes set on 18X but found that worse. Too much discernable wobble with eye relief becoming too critical and distracting from making good shots.
I only shoot scoped hunting rifles, nothing else.

I haven’t played with modest differences (like from 7 to 10 or 12x) but it does make a difference from 4x to 22x for me as far as getting small groups.

I have put a nightforce NXS on to a rifle that wore a 4x most of the time, and groups went from 1.5-1.25 with the fixed 4x trijicon to .75” with the NXS at 100 yards off a bench.

I put the 4x back on once I saw the load was capable of that grouping, as the use for that gun (3gun) the 4x is fine.

So it can make a difference, but how much difference and what amount of magnification is needed I can’t say.

It largely depends on your target and the subtension of your reticle. What magnification allows you to do is to reduce aiming error. If there is little or no aiming error to begin with then there is little or no gain with magnification.

If the reticle of a 4x "fits" the aiming point of the target appropriately (meaning that contrasting marks on the target allow the crosshair to be accurately centered) then there is so little difference in aiming error as to nullify any advantage of a higher magnification scope -- at least with the typical hunting rifle.

Of course, the world is not perfect and perfect fitment of the reticle to the target aiming point isn't always easy to achieve. In this case, magnification helps refine the aiming point and thus reduces aiming error.

But moving from something like 7x to 10 or 12x is unlikely to show a marked improvement in groups unless there is also a big difference in the reticles. Also, a well-focused 7x scope for which the zero parallax distance is the same as that of the target will serve you better than a poorly focused 12x for which the parallax is set at some distance other than that of the target.

Stonecreek's comments are spot-on. Using a target that's well-matched for the reticle-magnification combination is key and something that's often overlooked in our quest to wring out the best accuracy of a given rig.

High magnifications over a solid rest should make things slightly better but they'll also increase your perception of mirage.

If you understand and can read the mirage, this will also help. If you can't it will, like high power without a rest, possibly make things worse.

thanks guys. mr. stonecreek: thanks for the detailed answer. In response, I need some clarification. I make my own targets while load testing for the various distances I'm shooting. I make simple aiming squares similar to what benchrest targets look like: white background and a black square sized appropriate to the magnification of the scope. I attempt to size the square so that I can see that I've centered the reticle inside the square as best as possible but not excessively large. It just seems to me that greater magnification should allow a superior estimate of whether the reticles are correctly centered within that square. What am I missing here? thanks

quote:

Originally posted by devere:
thanks guys. mr. stonecreek: thanks for the detailed answer. In response, I need some clarification. I make my own targets while load testing for the various distances I'm shooting. I make simple aiming squares similar to what benchrest targets look like: white background and a black square sized appropriate to the magnification of the scope. I attempt to size the square so that I can see that I've centered the reticle inside the square as best as possible but not excessively large. It just seems to me that greater magnification should allow a superior estimate of whether the reticles are correctly centered within that square. What am I missing here? thanks

devere,

Well...I make my own targets, too.
And I think you're questions are specific to load development and sight-in from a solid bench rest. But let me generalize some first:

I can achieve a 2 to 3 times magnitude of order reduction in group size from shooting iron sights to shooting a scope irregardless of off-hand, sitting or bench rest Postions, Distance, or Target Design. My getting the best groups from my shooting positions does depend on scope magnification. Off-hand too much magnification is a real hindrance. Sitting, I can use more magnification but still find too high is a hindrance. From a solid best rest, I find I want maximum magnification.

Now, Closer to your questions:
From a bench rest, My Target Design, Scope Magnification, and Distance all intertwine. I did a comparison of scope magnifications at 200 yards:
My Best group at 2-3/4 power was 1.1"
My Best groups at 32 power touched.
Same distance, but I did use different targets to better the sight picture.

I design my targets with an excel spreadsheet and print on a color printer. The basic target design it to use all black borders on the spreadsheet and size he column width and the row height such that it prints exactly 1" squares. On std 8-1/2 x 11" paper this gets me a centered 1" grid of 8" x 10". On 11 x 17" paper it gets me a centered 10 x 16" grid.

I size different targets by filling the outer 1” squares and leaving the center 1” squares white to produce a sight picture that I can naturally quarter with the scope hairs. I experimented with different colors for this fill: Started with Black fill but couldn’t see the bullets holes past 100yds; When to a dark red fill – still couldn’t to see bullet holes well; When to yellow - could see bullet holes but some sight pictures were compromised, Settled on medium orange – Worked well for both!

The size of this outer border is best to be larger for the same magnification as distance increases (i.e. same sight picture for scope cross hairs). The reverse is also true (i.e. use small outer border for same distance at higher magnifications). Also adding a stick-on dot at the center white also improved aim. Again the size of the dot depends on distance and magnification – Same as the size of filled border.

So...Very general to possibly too much detail for some people. I you want to share more details PM me.

For my plains game rifle if was enticed by the 2 to 12 power range of the Swaro Z6i. It looked good on paper and performed well on the bench. For hunting it did not perform as well as I had hoped. Because of the large eyepiece it had to be mounted too high for a good cheek weld and when stalking it was large and clumsy. I replaced it with a Zeiss 1.5 to 6 scope that mounted lower and was easier to carry. Surprisingly I shot the same 1" three shot groups from the bench at 6x as I had previously shot at 12x. To do that you have to have very clear optics.

I put the Swaro on a single shot shot varmit rifle where it could be mounted low as it did not need to clear a bolt. Great scope for that application as 12x is useful for small targets at long range.

At least from my standpoint the higher power MIGHT increase accuracy from the bench but I do not hunt from a bench so I tend to match the scope to the practical application it will be used for in the field.

quote:

Originally posted by devere:
thanks guys. mr. stonecreek: thanks for the detailed answer. In response, I need some clarification. I make my own targets while load testing for the various distances I'm shooting. I make simple aiming squares similar to what benchrest targets look like: white background and a black square sized appropriate to the magnification of the scope. I attempt to size the square so that I can see that I've centered the reticle inside the square as best as possible but not excessively large. It just seems to me that greater magnification should allow a superior estimate of whether the reticles are correctly centered within that square. What am I missing here? thanks

When I test loads, or even zero, I use a square but instead of aiming at the center, I aim at a corner, usually the lower left. The vertical reticle line is aligned with the left side of the square and the horizontal one is aligned with the bottom of the square. This allows me to aim very precisely. Low mag = bigger square.

I did this today testing loads at 500 - square was red on a black steel plate with a 2.75 inch square.

quote:

Originally posted by AnotherAZWriter:
When I test loads, or even zero, I use a square but instead of aiming at the center, I aim at a corner, usually the lower left. The vertical reticle line is aligned with the left side of the square and the horizontal one is aligned with the bottom of the square. This allows me to aim very precisely. Low mag = bigger square.

I'm going to try this next time. I always shoot better groups with my rifle scopes that are more than 9x power. I love hunting and using my 6x Leupolds but for accuracy testing they have been lacking for me. Maybe a case of using the wrong style of target as well..

Great thread

All my scopes are maxed out at 20x magnification.

At least for me I think I need a much higher magnification scope to reduce group size especially once I start shooting at longer ranges - 300 yards.

The reticle matters too. I like a dot but not a illuminated dot.

I like shooting on a styrofoam plate with a single dot as the target/aiming point. A longer range I use e two plates - aim at one and collect my shots in another.

I need to buy the nightforce benchrest scope.

Mike

You can only aim as precisely as you can see.

quote:

Originally posted by Biebs:
You can only aim as precisely as you can see.

And that is everything.

So it’s also important what the reticle is.

There are some exceptionally good hunting glass. My blaser 2.8-20 scope is awesome. Problem is reticle is set up for hunting and not target shooting.

It’s tough to make tiny groups at 300 years when the aiming point is a 1 moa dot.

Mike

quote:

Originally posted by devere:
thanks guys. mr. stonecreek: thanks for the detailed answer. In response, I need some clarification. I make my own targets while load testing for the various distances I'm shooting. I make simple aiming squares similar to what benchrest targets look like: white background and a black square sized appropriate to the magnification of the scope. I attempt to size the square so that I can see that I've centered the reticle inside the square as best as possible but not excessively large. It just seems to me that greater magnification should allow a superior estimate of whether the reticles are correctly centered within that square. What am I missing here? thanks

I also like the benchrest square for precision aiming. I get the most precise aiming when the reticle subtends most, but not all, of the white center, leaving a small patch of white at each corner of the square. I use various size squares for various distances and scope powers in an attempt to match the target and reticle most closely.

Obviously, benchrest shooters don't use 4x scopes because higher magnification (up to a point) does allow more precise aiming. But for hunting calibers at hunting distances, modest magnification will allow aiming precise enough to judge the accuracy of the rifle and the loads.

I just returned last night with my son and grandsons from a prairie dog hunt -- small targets often at long distances. We took a number of rifles and among them the rifle in use with the lowest power scope maxed out at 10X while the rifle with the highest power had an 18X scope. We found no difference in the success rate between those two. In fact, the 18X sometimes proved to be less effective since it was slower to acquire the target due to its smaller field of view and provided no more precision aiming due to mirage. Most of my shooting was with a 12X scope which had ample magnification to define the small targets at 300+ yards and still enough FOV to see where the shot hit, even under some recoil.

A typical hunting reticle of a 4x scope would probably entirely cover up a prairie dog at 300 yards, while the 10X with a relatively fine reticle would not. This is a good illustration of when higher (but still modest) magnification helps with more precise shooting. But would 100 yard groups sighted on an appropriate aiming point be that much different with the two scopes? Probably very little.

I shoot the same group at 100 yards with my 2.5X Leupold Alaskan as I do with a 3x9 on 9X..Im talking big game hunting, I use 3X and 4X fixed scope and have never seen a reason to change that..Varmint hunting is a different ball game I like a 3x9, more power than 10 and that's iffy in warm weather rock chuck season..

Not to mention I hate big ugly scopes on my lean and hungry rifles..

I don't target shoot competition..