Prairie dog scope questions

[Holland&Holland]

Deciding on a scope for a prairie dog bolt gun.

There are some new reticles out there for long range varmint. Seems like these should be considered rather than dialing considering that p dogs could be at any given range. Thoughts on these for this application?

Power. Was kinda looking in the 20 - 25 top range. Worth going to 30 or are the trade offs such that it does not make sense? How much is too much?

Most scopes in this class seem to be 50mms. I always thought reducing light with Sun shades was more likely for p dog. Better to go with a 40? Other side of the coin any real benefit to go to a 56 for this. I suppose wider field of view might be a benefit.

Any real benefit going to a 30mms tube over a 1 inches for p dogs?

[Ghost]

How much are you looking to spend?

[JJ]

Some good stuff here, you are asking very good questions.

Reticles: Ballistic reticles with holdover subtensions and windage stadia marks are very useful for quick adjustment. Depending on the volume you intend to shoot, they are a must have, for high volume shooting. That said, I only find them beneficial in FFP optic. 2ndFP optics, the reticle subtensions will only be valid at one magnification (usually the highest magnification). That handy hash mark at 2moa? Back that scope down to 8X and its now at 4moa, and bring it down to 4x and its all the way down to 8moa. The reason this is significant?

Magnification: Don't over-do it. i have backed down to 3-15x on most of my dog rigs. I was running a lot of 4-20, 6-24'etc and found that on hot days the mirage was just brutal. The higher the magnification, the worse both ground mirage, and more importantly barrel mirage will get. Those high power optics just magnify the mirage, and make parallax issues seem trivial. After 9-10 am I was backing my scopes all down to 10-15X anyways. The window that i found those high magnifications beneficial, was pretty small early and late in the day.

Objective lens dia: I try and stick with 50mm, just for the larger FOV. I do run a couple 42 0r 44's, and they are ok. I would avoid going any larger than 50mm, just because even a 50 makes you mount higher above the bore axis than I would prefer. I try and run the lowest possible ring to the bore. Doing so will help minimize line of sight errors.

30mm/1": The biggest difference is lens size, followed by overall adjustment range. In a perfect world, your optical system would be perfectly aligned to the center of each and every lens. As you move the erector system you start moving away from the center of the lenses and the image quality will degrade, the further you adjust. A 30mm tube allows you to get bigger internal lenses, which will have a better chance of using the heart of your lens cells. Also, generally, a 30mm tube will have more overall adjustment range, so if you need long range dope, you don't have to spend as much time on setting up the rings/bases to maximize your usable adjustment range.

[UnaStamus]

High magnification is a Catch-22 in that negatives come with the positives, and to a degree there is a matter of diminshing returns. When you increase magnification, you reduce the exit pupil. As you increase magnification, your light transmission and resolution dimish. Low end/lower quality scopes counter this by increasing objective lens size. Better scope companies counter this by using higher grade achromatic or apochromatic glass, plus advanced multi-phase coatings, along with increased objective lens diameter. A good quality scope w/ 40mm objective lens will have better optical quality than a low quality scope with 50mm objective lens due to the quality of glass and coatings. If you want high magnification, you will have to invest more money into quality glass in order to get the most benefit. Good glass does not lose much in the way of light or resolution.

[OldmanFCSA]

I have a 10X to 40X scope with a 50mm Objective, 30mm tube, and side mounted AO if you are interested in trying one.

[Holland&Holland]

How much are you looking to spend?

Kinda thinking between 1k and $1500.

[Holland&Holland]

Some good stuff here, you are asking very good questions.

Reticles: Ballistic reticles with holdover subtensions and windage stadia marks are very useful for quick adjustment. Depending on the volume you intend to shoot, they are a must have, for high volume shooting. That said, I only find them beneficial in FFP optic. 2ndFP optics, the reticle subtensions will only be valid at one magnification (usually the highest magnification). That handy hash mark at 2moa? Back that scope down to 8X and its now at 4moa, and bring it down to 4x and its all the way down to 8moa. The reason this is significant?

Magnification: Don't over-do it. i have backed down to 3-15x on most of my dog rigs. I was running a lot of 4-20, 6-24'etc and found that on hot days the mirage was just brutal. The higher the magnification, the worse both ground mirage, and more importantly barrel mirage will get. Those high power optics just magnify the mirage, and make parallax issues seem trivial. After 9-10 am I was backing my scopes all down to 10-15X anyways. The window that i found those high magnifications beneficial, was pretty small early and late in the day.

Objective lens dia: I try and stick with 50mm, just for the larger FOV. I do run a couple 42 0r 44's, and they are ok. I would avoid going any larger than 50mm, just because even a 50 makes you mount higher above the bore axis than I would prefer. I try and run the lowest possible ring to the bore. Doing so will help minimize line of sight errors.

30mm/1": The biggest difference is lens size, followed by overall adjustment range. In a perfect world, your optical system would be perfectly aligned to the center of each and every lens. As you move the erector system you start moving away from the center of the lenses and the image quality will degrade, the further you adjust. A 30mm tube allows you to get bigger internal lenses, which will have a better chance of using the heart of your lens cells. Also, generally, a 30mm tube will have more overall adjustment range, so if you need long range dope, you don't have to spend as much time on setting up the rings/bases to maximize your usable adjustment range.

Very good points, lots to think about, thank you.

Was considering the Leupold VX-3L ( the one with the funky cut out), always had good luck with Leupolds, this one allows you to mount lower to the barrel as you stated, but it is a 56 in the 6-20 model, was almost hoping they made a 50 in this, but maybe that is too much magnification anyway. It is a 30mm which is nice. I usually am a dialer rather than a ballistic reticle guy but I could really see for Pdogs the advantage to such a reticle. Was about to pull the trigger on this set up but then started 2nd guessing myself. Started looking at the new Nikon Monarch 5. I have always found my Nikons to be good glass for less money and the Monarch 5 looks like a nice unit for a bit less than the Leupold. Was looking at the 5-25x50, but it is a 1 inch tube. Of course that will then get you looking at the 6-30x50 for not much more and still much less than the Leupold 6-20, which is what prompted this discussion topic for me. Not sure on either of the plan of the reticle. I will have to look into that a bit more.

[Holland&Holland]

High magnification is a Catch-22 in that negatives come with the positives, and to a degree there is a matter of diminshing returns. When you increase magnification, you reduce the exit pupil. As you increase magnification, your light transmission and resolution dimish. Low end/lower quality scopes counter this by increasing objective lens size. Better scope companies counter this by using higher grade achromatic or apochromatic glass, plus advanced multi-phase coatings, along with increased objective lens diameter. A good quality scope w/ 40mm objective lens will have better optical quality than a low quality scope with 50mm objective lens due to the quality of glass and coatings. If you want high magnification, you will have to invest more money into quality glass in order to get the most benefit. Good glass does not lose much in the way of light or resolution.

Understood. Was not planning on going too high end on this one. It is for fun and no lives on the line so... VX-3 is kinda the standard I am judging by and price point I am thinking. if I am crazy, let me know.

But I understand paying more for performance. For my .375 H&H I went Swarovski. When I finally get my trip to Africa together performance will be critical of the gear.

[Holland&Holland]

I have a 10X to 40X scope with a 50mm Objective, 30mm tube, and side mounted AO if you are interested in trying one.

I appreciate the offer. I am thinking 40x is a bit more magnification than I was thinking I needed for pdogs.

[Erud]

Some good stuff here, you are asking very good questions.

Reticles: Ballistic reticles with holdover subtensions and windage stadia marks are very useful for quick adjustment. Depending on the volume you intend to shoot, they are a must have, for high volume shooting. That said, I only find them beneficial in FFP optic. 2ndFP optics, the reticle subtensions will only be valid at one magnification (usually the highest magnification). That handy hash mark at 2moa? Back that scope down to 8X and its now at 4moa, and bring it down to 4x and its all the way down to 8moa. The reason this is significant?

Magnification: Don't over-do it. i have backed down to 3-15x on most of my dog rigs. I was running a lot of 4-20, 6-24'etc and found that on hot days the mirage was just brutal. The higher the magnification, the worse both ground mirage, and more importantly barrel mirage will get. Those high power optics just magnify the mirage, and make parallax issues seem trivial. After 9-10 am I was backing my scopes all down to 10-15X anyways. The window that i found those high magnifications beneficial, was pretty small early and late in the day.

Objective lens dia: I try and stick with 50mm, just for the larger FOV. I do run a couple 42 0r 44's, and they are ok. I would avoid going any larger than 50mm, just because even a 50 makes you mount higher above the bore axis than I would prefer. I try and run the lowest possible ring to the bore. Doing so will help minimize line of sight errors.

30mm/1": The biggest difference is lens size, followed by overall adjustment range. In a perfect world, your optical system would be perfectly aligned to the center of each and every lens. As you move the erector system you start moving away from the center of the lenses and the image quality will degrade, the further you adjust. A 30mm tube allows you to get bigger internal lenses, which will have a better chance of using the heart of your lens cells. Also, generally, a 30mm tube will have more overall adjustment range, so if you need long range dope, you don't have to spend as much time on setting up the rings/bases to maximize your usable adjustment range.

Very good points, lots to think about, thank you.

Was considering the Leupold VX-3L ( the one with the funky cut out), always had good luck with Leupolds, this one allows you to mount lower to the barrel as you stated, but it is a 56 in the 6-20 model, was almost hoping they made a 50 in this, but maybe that is too much magnification anyway. It is a 30mm which is nice. I usually am a dialer rather than a ballistic reticle guy but I could really see for Pdogs the advantage to such a reticle. Was about to pull the trigger on this set up but then started 2nd guessing myself. Started looking at the new Nikon Monarch 5. I have always found my Nikons to be good glass for less money and the Monarch 5 looks like a nice unit for a bit less than the Leupold. Was looking at the 5-25x50, but it is a 1 inch tube. Of course that will then get you looking at the 6-30x50 for not much more and still much less than the Leupold 6-20, which is what prompted this discussion topic for me. Not sure on either of the plan of the reticle. I will have to look into that a bit more.

Keep in mind that with the weird Leupold with the cutout, even though it is a 56mm objective, it will not gather as much light as other 56mm's, all else being equal. The total surface area of the objective is the actual important number, not the diameter. Since scope lenses are normally all round, the diameter is a good way to compare surface area unless you are looking at something goofy like the VX3-L. A smart guy who knew some fancy math could figure out the actual area of the front lens - my guess is it's closer to that of a 44mm or so. In my opinion, that scope is a gimmick. You get the down side (size) of a 56mm, but none of the up side(light).

[Holland&Holland]

Erud, I know it is a gimmick, but it looks cool. If you wish it to be functional enough won't it change?

On a more serious note do you get a wider fov or is the tube diameter the limiting factor in that?

[Ghost]

How much are you looking to spend?

Kinda thinking between 1k and $1500.

Lots of options in that range. I feel Vortex gives you the best bang for your buck though.

[Erud]

Erud, I know it is a gimmick, but it looks cool. If you wish it to be functional enough won't it change?

On a more serious note do you get a wider fov or is the tube diameter the limiting factor in that?

That's a good question, and I guess I don't actually know the answer. I don't believe the tube diameter determines FOV, but I'm not sure if the VXL-3 would have a comparable FOV to a similar 56mm scope. Comparing published specs should give you a fairly good idea.

[P3 Orion]

I have used Leupold vx-3 6.5-20 x 40 with varmint hunter reticle. It has elevation and windage on the reticle. The last couple years I have used VX-2 (6-18x40) with the CDS dial. That works very well for me when I have a good range finder. The original VX-2 with CDS does not have windage markers. Now Leupold has come out with what they call CDS with "wind-plex" reticle. I just bought one but have not used it yet, but it looks like there should be some good windage reference points. I started out using BSA with up to 32 power, to much power as it limits field of view. At this point I am very happy with the VX-2.. My Son uses the same and also considers it an excellent choice. I find the 18 power to be more than adequate for P Dog shooting. Just my $.02.

[SIGP240]

Consider first focal plane reticle. You may cover less target with the reticle on higher magnification. You still have the mil reference marks to compensate for the bullet drop/wind/lead. Bushnell makes a designated marksman scope 6x24 that performs well in daytime. You will rarely notice the actual " brightness " of a scope unless you are a dusk/night varmint Meister. They sell for about 850$. Side focus style, as i usually can't reach out to the objective to focus if you are dogging. Yes, 24x is almost too much, as your resolution may degrade. Just like camera lenses. Even a 5000$ Nikon zoom lens poops out ar max zoom on my 35mm. Prime focal length scopes work well for me, if you have a spotter. Mirage is always a component to deal with in warm desert environments. Funny, I love it for seeing how the wind is behaving by defocussing the scope and popping a shot; watch the turbulence in the contrail/wash.