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View Full Version : Is a 20X scope overkill?



westernwannabe
04-15-2011, 09:37 PM
I have a 6x20x50 scope leupold VXIII thinking of buying a tikka T3 7mm mag. Im unsure about the scope being to much for the rifle. I had a 4.5x14 nikon on a 280 rem and at 400yards the scope didn't have enough zoom for me. I hear of guys shooting 400 yards with a 3x9 but I couldn't imagine that! I know Dave Long hunted with a 20x in his book but he might have a better rifle for the scope? I want to set this rifle up for big country hunting(tetons, colorado high country, etc.).

wolftalonID
04-16-2011, 09:56 AM
I think its a great match up!. You have everthing except weight in your favor!. Great light gathering with the 50mm objective. Low power for getting a wider field of view when you need it, and for larger targets that have a more forgiving kill zone. Major magnification for clarity of your target at farther ranges as well, you can DIAL in on the kill zone at range when needed.
And if for what ever reason you feel like a 600 yard shot on a whistlepig with that 7mm! lol your gonna be covered for that too!.

Tell ya what though. If you find your not wanting that scope...I will buy it from you.

MTWillie
04-16-2011, 11:30 AM
I don't think so at all. I have a custom Model 70 in 7 Mag and on it I have a 10-40x50 mil-dot scope on it. It's nice to be able to see up close how your shots are hitting at 300 :)

westernwannabe
04-16-2011, 10:24 PM
Thanks wolftalonID it's nice to have some assurance from someone with a western perspective. The 3 times I've hunted out west it has felt like a 20x would be a good thing thanks.

Jerry
04-16-2011, 11:03 PM
They are great if you need for long distance, but I have missed opportunities because of forgetting to turn back down for close up shots. It's hard to make a kill shot when all you have is a scope full of hair!

Elkoholic307
04-29-2011, 10:05 AM
First of all, there isn't a big difference in light gathering capabilities between a 40mm and a 50mm... Also, shooting on 20 power does not give you a more 'forgiving kill zone'. It doesn't make your physical target any bigger.

An advantage when you're shooting on full power is, you can pick a specific spot on the hide to aim at; discoloration or a patch of hair growing the opposite way right behind the shoulder, etc. That's how I like to use it, anyway.

I wouldn't say the 6.5-20x50 is too much for that rifle, but I prefer the 40mm so I can use low rings. Then, you can mount the scope lower and you can get down on the stock for a solid cheek rest. Not to mention, 40mm is lighter and less 'cumbersome' to pack.

Bitterroot Bulls
04-29-2011, 12:40 PM
20x might not be too much all the time, but it isn't necessary. Military snipers have been making hits at long distances (1000 yards+) with 10x fixed scopes for decades. Lower magnification has a lot of advantages. With higher magnification, your natural shake, even your heart rate, and its effect on the crosshairs will be magnified. Mirage is magnified as well. The field of view is much wider with a lower range variable. Higher magnifications also reduce your low-light performance because the magnification shrinks the exit pupil, which is essential for low light use. You will also get better optical performance for your money with lower magnification scopes.

A 3-9 variable gives all the magnification needed for typical hunting ranges, and actually much further if necessary.

I recently went from a 6.5-20X50 on my elk rifle to a 4-12 with better glass. Glass quality trumps magnification every time. You see more with a great 9x than a mediocre 20x, and seeing better is what you are magnifying the image for.

Elkoholic is spot-on on low mounting. Cheek-weld is also essential for precision shooting, and a lower mount usually helps getting a good cheek weld.

High magnification is helpfull only in a few, rare circumstances, IMO.

westernwannabe
04-29-2011, 02:16 PM
If you can shoot a 1000 yards with a fixed 10 you have alot better eyes than I do. I had a nikon 14 power with the BDC the 400 yard circle on it covered 8" to 10" at 400 yards. It was really hard to center the circle at that range. The 20 power gives me total confidence at that range. I'm wanting to take this on a hunt for muleys in region G. Just thought it would work well for that, but I know more about bows and muzzleloaders than rifles.

Bitterroot Bulls
04-29-2011, 04:00 PM
Yeah, those circles are a little different. Some guys like them. If that Leupold VX-III scope suits you, then use it. I was just pointing out that high magnification scopes have their issues, and most of the time a little bit lower magnification helps most shooters in the field. Just a few days ago I was shooting steel at 600 yards with my 7-08 and a 2-7x32 Vortex Viper. It wasn't hard to identify the targets. The Viper has a BDC with dots on the crosshairs instead of circles. The dots are .75 MOA, so cover about 3" at 400 yards. The crosshairs are .2 MOA thick, so the cover about .8 inches at 400 yards. A guy can be pretty precise with the setup.

wolftalonID
04-29-2011, 07:46 PM
Elkoholic, ??? Not much difference in light gathering of a 40mm vs 50mm? If 56% more LGP thats Light Gathering Power, for those that dont know, I would say its a bit more than not much.
You can calculate LGP of an objective lens by taking the size of the lens in mm and divide by 7, then square the results. To be a bit more blunt, thats why NV systems use such large objectives.

And to clear up your other parts, I didnt say magnification would give you a more forgiving kill zone, I said larger animals will, and lower magnification is nice to have for wider fields of view, AND shooting at larger animals or targets that have larger more forgiving kill zones.
That being said it also means I am implying that smaller targets are nice to shoot at WITH magnification cranked up so you can pin point your kill zone more precisely.

Try shooting a whistle pig at 600 yards at 12x power. You would be lucky to see the thing.

Bitterroot.
Having high magnification on a LR shooting gun like a 7mm is very desirable in SWAG situations. Seeing the "mirage" if you will helps you see the magnitude of the heat index at range. If you also have a very sensitive parallax adjustment, you can move from near to far, check the difference in heat index or rise rate over the terrain. Spotters use high magnification on their spotting scopes to do this, and can adjust for the rise in the shot from high heat to keep the shooter from over shooting the target on a hot day.
So having it in an all in one set up for the shooter will in many ways help a LR shooter take that shot.
Cheek weld on a TIKA rifle is usually not much of an issue with large objective lens scopes, especially ones by leupold.

Bitterroot Bulls
04-29-2011, 08:16 PM
A few thoughts, as this is a good discussion for hunters, and I mean no disrespect to any posters:

LGP is a theoretical measure of the amount of light that will pass through an objective lens. The term "gathering" is a bit of a misnomer, as the lens doesn't gather anything. It simply allows light to pass through it, so a bigger lens naturally has more area for light to pass through. LGP is typically used in astronomy as sort of a "this telescope could be this good" way.

In sport optics for terrestrial viewing (binoculars, spotting scopes, and riflescopes), exit pupil is much more important than objective diameter, although they are linked. Exit pupil is a simple calculation of objective lens diameter (in mm) divided by magnification. You could also use a micrometer and measure the exit pupil and come up with the same result. For instance a 50mm scope at 10x has a 5mm exit pupil. The human eye when it is healthy and young will dilate to a maximum of about 7mm in low light. As you get older, this number gets a little smaller.

So, in low light your 7mm pupil is only making use of 5mm of exit pupil, because that is what your scope is showing it. If you go to either a bigger objective or lower magnification, the exit pupil will enlarge, providing a brighter image.

That is why when light is low, and you turn your magnification down, you see a brighter image: exit pupil.

During bright to normal viewing conditions, your eye's pupil will be constricted to a size that is smaller than the exit pupil of most scopes regardless of whether they are 40mm or 50mm (and aren't really high magnification), so the images will appear similarly bright. When light gets low, the bigger objective will provide a larger exit pupil, and apparently brighter image.

As far as shooting a marmot at 600 yards at 12x, I would feel quite confident at 12x. I would feel confident at 6x. Think of it this way: The marmot would be magnified twelve times, so it would appear 12 times closer. 600 divided by 12 is 50. Could you shoot a marmot at 50 yards with open sights?

wolftalonID
04-29-2011, 08:25 PM
Thats a very well sorted post Bitterroot. However Marmots vs Idaho whistlepigs are two different buggers. Idaho whistle pigs are goffers. They sit about 6 inches tall vs the 18in Rock Marmot most other Western States call whistlepigs.
I should have clarified the content of the nickname better, :)

That and I also should have stated the LGP percentages are based on a 1x comparison of the Obj Lens alone, not the entire calculation of the internal lenses and the resistance they produce from Obj to occular.
However I believe you clarified what I left out rather well, so thank you on that.

Bitterroot Bulls
04-29-2011, 08:31 PM
wolftalonID,

I am responding to your edit:

It is true that reading mirage is helpful in long range shooting. I actually have quite a bit of training in this area. However, mirage is typically used to dope the wind, not a heat related drop adjustment. Heat will affect trajectory over long distances, but it has to do with atmospheric density, and mirage will not help you evaluate that, at least I've never been through a training like that. You can evaluate mirage through a parallax adjustable riflescope, although it is much more effective with a high-magnification spotter.

If you can get a good cheek weld with a 50mm objective scope, great! You will always be able to mount a 40mm scope lower, however. My 4-12 is actually a 50mm objective on a Remington 700 Sendero, and I get a good weld with it.

Bitterroot Bulls
04-29-2011, 08:36 PM
wolftalonID,

Sorry, I always called marmots whistlepigs.

Although I still think I could resolve a gofer at 600 yards through my scope at 12x, I will say that when your targets get super-tiny, a little extra magnification is nice (ask benchrest shooters), as long as you realize the tradeoffs.

Still, for a big game rifle, even for longer range shots, a person usually doesn't need too much magnification.

wolftalonID
04-29-2011, 08:39 PM
Yes you can read the waves in the lateral movement angle to dope wind speeds when you dont have rangeflags(ie in the field settings). You can also use them vertically by comparing how compact they get. With parallax you can compare them at say 100 meter range point vs the 400 vs the 1200. Increase the magnification equally each step to keep the picture relatively the same. If your doing it right and say there is a hot spot farther down range, it can "lift" the bullet if you will. Use the mirage for both heat rise(atmospheric density), as well as the dope,(windage changes).
Yes your spotter should do this for you, however if your solo, you may not have the luxury of movement from a HP spotter to your weapon, so a single scope can do it for you.

Bitterroot Bulls
04-29-2011, 08:56 PM
Interesting,

So you are saying that you can read a different "rate" of mirage between you and the target, and that will tell you that there are "spots" of warmer air that are going to be so different from the surrounding atmosphere that it is going to affect your drops to a noticeable degree? I have not heard that.

I don't think mirage is great at helping to dope wind speed, either. It is most useful to me in doping wind direction. I estimate wind speed by evaluating movement of the surrounding vegetation, and I use a portable wind meter to get the wind speed at my location.

Good discussion.

wolftalonID
04-29-2011, 09:12 PM
If you have no vegitation, and no fancy wind meter, and no fancy balistic calculator, you have to work your art of doping to a more refined degree.
Here is an article you might find a great read. This guy puts into words the best what it is I do.

ARTICLE (http://www.weaponscache.com/forum/ammunition-reloading/1843-doping-refining-shot-placement.html)

xtreme
05-01-2011, 10:42 AM
Bitterroot Bools, that is a good post, but you failed to mention the exit pupil as pertaining to age. My longest shot on a mule deer was 467 yards using a VX 2 3x9 set on 5 power in the closing light. Now I have much better glass, but at my age I am not able to use the extra exit pupil of my VX 7L or Z5. I do sometimes use the larger magnification, 4.4x18x56 for the VX7 and 5x25x52 for the Z5, both are mounted low. I no longer hunt elk, if I did weight would be a concern and a really good 3x9x 40 would be my choice

Bitterroot Bulls
05-01-2011, 07:27 PM
xtreme,

I thought mentioned age and exit pupil in the post, but I think it is good to emphasize the point. I also agree with your thoughts on magnification. I think getting a scope with high magnification is one of the biggest and most common mistakes new shooters make. A 3-9X40 with the best glass you can afford is a great way to go for an elk rifle. You have a nice large exit pupil, don't have to worry about parallax, and have sufficient magnification for even extended range shots.

westernwannabe
05-03-2011, 03:14 PM
Hey didn't know I was capable of starting such a intellectual conversation. You guys are going to have to dumb it up alitttle for me to understand! Lol

wileywapiti
05-04-2011, 10:04 AM
i say..if all else fails, get closer to your target. i have never used those high magnification scopes and done pretty well. i use the 3x9 VxIII from leupold and i have missed opportunities to shoot at game because they were too far for me and my optics, but i also have always had my legs and feet to get me closer. to me, that is what hunting is about....

A good stalk will always be a better story (to me at least) than a long shot story. But its what you want, so go with the scope you like and do it your way. you wont be disappointed doing it your way.

P.S....just make sure you have good glass, it will make all the difference in the world. light gathering, in my opinion, is more important than magnification, most of your shots will be at first or last light so don't lose out because you couldn't see.

Elkoholic307
05-05-2011, 01:56 PM
Hey didn't know I was capable of starting such a intellectual conversation. You guys are going to have to dumb it up alitttle for me to understand! Lol

Haha, it's starting to go over my head also, but Bitterroot seems to be nailing it. To make things easy.. your question is, "Is a 20X scope overkill?" My not-so-intelligent answer is.. no, not at all.

It's up to you how big of an objective you want. I still don't think there is a significant difference between the two. I have two 6.5-20x40mm VX3s that work great for me. If you're in really low light, turn the power down; just as you would a 50mm.

Elkoholic307
05-05-2011, 01:59 PM
i say..if all else fails, get closer to your target. i have never used those high magnification scopes and done pretty well. i use the 3x9 VxIII from leupold and i have missed opportunities to shoot at game because they were too far for me and my optics, but i also have always had my legs and feet to get me closer. to me, that is what hunting is about....

A good stalk will always be a better story (to me at least) than a long shot story. But its what you want, so go with the scope you like and do it your way. you wont be disappointed doing it your way.

I don't think he's asking for a lecture on how to hunt...

wileywapiti
05-05-2011, 08:11 PM
yup, you are right. im sorry for getting off track. back to the topic, i dont think its necessary but if you like it then do it.