Leupold cds question

savagelh

savagelh

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I've never owned a scope with the cds. I'm looking at the vx3hd 4.5-14 1" non ao or the 3.5-10×40 1". I'm assuming there's no benefit to go with the 30mm for more elevation if the dial is only good for 1 revolution correct? Besides maybe the obvious light gathering abilities.

Is there any reason to stay away from the 4.5-40?

Does the factory turret only go one revolution or just the custom cds?

The application will be on a switch barrel rifle where one barrel is 22-250 ai and the other would be 6.5x55. I should be able to get close to 800 yards with the 22-250 and about 700 with the 6.5x55. Does this make sense? I was going to use the moa dial for 22-250 and the cds for the 6.t because the latter would be for hunting and the 22-250 would be more target/varmint.
 
Bigger tubes do not improve light gathering. That is determined by the glass quality and the exit pupil size.

The CDS-ZL turret offers a single rotation with 15 MOA of elevation for the 1" VX-3HD. That should get a typical big game cartridge out to 500 yards reasonably easy, it'll take my .30-06 out to just past 600. If you want more elevation, the CDS-ZL2 offers 2 rotations of 20 MOA each but that requires stepping up to a VX-5HD, which you would want to do for the parallax adjustment anyways.

Which one to use depends on the typical ranges they will be used at, you will have a better field-of-view out of the 3.5-10 but at the same time, the optical quality is excellent so the top end on the 4.5-14 will still be crisp and clear while offering slightly more magnification. That might be important if you do plan to shoot at 800 yards regularly.

As for the dials themselves, I've never bothered with the custom dial personally, I generally work up a DOPE card for my rifle and dial accordingly.

The 3.5-10x40mm is probably my current favorite hunting scope.
 
mikeyb said:
Bigger tubes do not improve light gathering. That is determined by the glass quality and the exit pupil size.

The CDS-ZL turret offers a single rotation with 15 MOA of elevation for the 1" VX-3HD. That should get a typical big game cartridge out to 500 yards reasonably easy, it'll take my .30-06 out to just past 600. If you want more elevation, the CDS-ZL2 offers 2 rotations of 20 MOA each but that requires stepping up to a VX-5HD, which you would want to do for the parallax adjustment anyways.

Which one to use depends on the typical ranges they will be used at, you will have a better field-of-view out of the 3.5-10 but at the same time, the optical quality is excellent so the top end on the 4.5-14 will still be crisp and clear while offering slightly more magnification. That might be important if you do plan to shoot at 800 yards regularly.

As for the dials themselves, I've never bothered with the custom dial personally, I generally work up a DOPE card for my rifle and dial accordingly.

The 3.5-10x40mm is probably my current favorite hunting scope.
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Thanks for the advice. After thinking about it, the custom dials wouldn't do me much good. I'm too much of a tinkerer and never stick to one load. I think I'd be better off with just moa marks on the dial and do dope cards like you suggest.
 
savagelh said:
Thanks for the advice. After thinking about it, the custom dials wouldn't do me much good. I'm too much of a tinkerer and never stick to one load. I think I'd be better off with just moa marks on the dial and do dope cards like you suggest.
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This is a great decision. What most people don't understand is that past 4-500 yards, environmentals play a huge part in ballistics. So a custom turret is really only good for that one load in one specific environment. You change either, and the marks on the turret are no longer accurate. Custom dials and ballistic drop reticles are wonderful marketing gimmicks.
 
Clocked92 said:
This is a great decision. What most people don't understand is that past 4-500 yards, environmentals play a huge part in ballistics. So a custom turret is really only good for that one load in one specific environment. You change either, and the marks on the turret are no longer accurate. Custom dials and ballistic drop reticles are wonderful marketing gimmicks.
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For the thread, you lose a couple clicks on the cds-zl for the locking mechanism so you only dial up 58 clicks instead of 60, not a big deal but worth mentioning. I had a zl2 on a vx5 but can't remember if it was the same, wouldn't matter with nearly 40 moa of travel to play inside lol.

As for the quote...I disagree, if one spends a little time studying their elevation range and average temp, you can middle your data for these ranges and worst case at 600 yards you'll only be out 1-2 clicks. Inside 500 you could probably still accurately kill game with a number of reasonably similar loads from your middling data. So speed dial turrets are a great idea if you have a set up rig with designated load as it's much faster to not have to consult any chart, just range and dial to the number. It's called 'speed dial' turret for a reason, and you get bigger digits printed on the turret to make easy to read also. Only data to keep handy is a few points of wind. I hunt Alberta, coyotes on the prairies to sheep up the mountains which is a 3500' to 8500' spread, (5000' range) and set my data for 5000' and 5 degrees celsius and it's been deadly to all test shots to 930 yards and on game to just under 600 for big game and just over 600 on a coyote. I like to be less out for the -20 3500' late winter coyotes hung up at distance but chances are on a sheep with it's larger kill zone I won't be shooting as far so being out 2 clicks at 600 isn't a thing. Run the numbers at every 1000' in your range and temps from -20 to plus 20 at the extreme ends and you'll see what I mean.

Same would go for a bc or mil-dot reticle. You dial with either one, the turret or the magnification ring, but both systems can be used very quickly, the key...as with any system/gear...is to pick one and then become one with it so it's instinctual at crunch time. I shoot speed dial or multi-aimpoint reticles plenty good enough inside 600 as to go either way. You get a bit more precision with dialling and if you're over someone's shoulder having them shoot your rifle then dialling would likely be better so you can then just dial for them and tell them where to hold for the wind as gapping dots etc. may not be natural to a rookie.
 
Most of my precision shooting is done on targets and not in hunting scenarios so I'm kind of anal when it comes to precision and trying to be perfect. While your 'click' or two difference may be sufficient for a hunting scenario, I know that I'm not satisfied with "close enough".

Even with one specific load, the variations in ballistics due to environment is drastic. Obviously, the faster, better BC bullets will be less susceptible, but the theory still holds. For example, a 6.5mm Berger 130gr bullet going 2900fps will drop 7.5mils (62 inches) at 4000ft Density Altitude and +20C. That exact same load, requires only 7.2mils (55 inches) of elevation if the DA changes to 7000ft. DA is a combination of altitude, temperature, humidity and pressure so you better have all those factored in and keep track throughout the day. I've shot in places where the DA will change by over 3000ft from the morning to early afternoon. This example also assumes that temperature stays static, Ammunition will often have different muzzle velocities at different ambient temperatures so you have to account for that as well.

I know you're trying to average everything out, which makes sense for some situations. Especially inside 600 yards. I just get very tired of people assuming their BDC reticle or custom turret is a god send for long range shots and then get mad when they miss by 2 feet at 1000 yards. I'd rather people understand all that goes in to long range precision and learning their system/ammo and all the factors that come into play. That way, they know their gear and can place shots more precisely on target.

And then of course wind calls and wind reading comes in to play... but that's a different rabbit hole.
 
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Clocked92 said:
Most of my precision shooting is done on targets and not in hunting scenarios so I'm kind of anal when it comes to precision and trying to be perfect. While your 'click' or two difference may be sufficient for a hunting scenario, I know that I'm not satisfied with "close enough".

Even with one specific load, the variations in ballistics due to environment is drastic. Obviously, the faster, better BC bullets will be less susceptible, but the theory still holds. For example, a 6.5mm Berger 130gr bullet going 2900fps will drop 7.5mils (62 inches) at 4000ft Density Altitude and +20C. That exact same load, requires only 7.2mils (55 inches) of elevation if the DA changes to 7000ft. DA is a combination of altitude, temperature, humidity and pressure so you better have all those factored in and keep track throughout the day. I've shot in places where the DA will change by over 3000ft from the morning to early afternoon. This example also assumes that temperature stays static, Ammunition will often have different muzzle velocities at different ambient temperatures so you have to account for that as well.

I know you're trying to average everything out, which makes sense for some situations. Especially inside 600 yards. I just get very tired of people assuming their BDC reticle or custom turret is a god send for long range shots and then get mad when they miss by 2 feet at 1000 yards. I'd rather people understand all that goes in to long range precision and learning their system/ammo and all the factors that come into play. That way, they know their gear and can place shots more precisely on target.

And then of course wind calls and wind reading comes in to play... but that's a different rabbit hole.
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I too get tired, of the target guys lost down rabbit holes in gear and chasing precision and trying to apply the gear/methods to hunting. Which is mostly defined as mpbr to 600, even on rokslide where it seems half or more do PRS...they may shoot ffp mil this etc. but their top authority there admitted very few can consistently kill past 600 and most consistency drops off about 450 and then moderate amount kill well in-between 450-600. Then you apply practical field accuracy limits of shooters, the rifles if consistently under 1.5 moa you chase a point of diminishing returns anything less and keep boiling things down FOR THE TASK AT HAND...then most of the nonsense can be left for the range and guys could build a hunting rifle 10x simpler as there's very little data needed to get from mpbr to 600 and you can simplify it so all you need is a basic rangefinder and do all the computing and setup before the season starts. You will not see your .1-.3 mil at 600 yards advantage in hunting. There's a point of diminishing returns in all this when you apply long distance target shooting to 'hunting'. There's a convergence of a couple other factors as well that seem to have naturally developed these distance limits. You've got TOF and live animal relationships (coincidentally archery hunters seem to also tap out in the same TOF's as the gun guys, 50-70 yards) and then environmental which is primarily wind. But add in the practical field accuracy and we know most of us shooting moa consistently have more than enough. Then we seem to have a whole schwack of people that are not perspectiving things well as the target shooting on static targets has really only the usefulness of learning to break decent shots and understanding ballistics to the appropriate levels but hunting is a completely different game and you're better off doing less of the right kind of practice than more of the wrong...ie; prs, f-class etc. If you enjoy shooting matches etc., giver, hyper focus rigs/methods for that... if you enjoy hunting then set up rigs for that too...hyper focused on that....leave the range stuff at home. Anything works for range stuff.

Yup wind is another topic. Most will not be comfortable with or proficient at dealing with up to 20" wind calls. So there's a few methods one can deal with that but yes another topic. It lends into all the convergences of dropping bullets into the pie plate on game in hunting situations. So yes you sure can middle your data and the most effective killers will be the fastest killers to 600. Period so you boil down systems that simplify and speed you up and get rid of any fat. Because if you don't, your friend Murphy is going to run into you out there from time to time and look at you and your gear and shake his head. ;)
 
savagelh said:
I've never owned a scope with the cds. I'm looking at the vx3hd 4.5-14 1" non ao or the 3.5-10×40 1". I'm assuming there's no benefit to go with the 30mm for more elevation if the dial is only good for 1 revolution correct? Besides maybe the obvious light gathering abilities.

Is there any reason to stay away from the 4.5-40?

Does the factory turret only go one revolution or just the custom cds?

The application will be on a switch barrel rifle where one barrel is 22-250 ai and the other would be 6.5x55. I should be able to get close to 800 yards with the 22-250 and about 700 with the 6.5x55. Does this make sense? I was going to use the moa dial for 22-250 and the cds for the 6.t because the latter would be for hunting and the 22-250 would be more target/varmint.
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I am not a fan of CDS type turrets, regardless of the application.
I much prefer to use a drop chart with real time dope ( read actually shot at the distances) .
Cat
 
I would just get the Tri-moa reticle instead. The cds idea sounds great on paper but just doesn't work out as good as a dope card or marking it yourself.
 
I use custom dials, straight MOA turrets and subtension reticles, on different rifles for different purposes. Some are combinations of both in the same scope. Seems to me that my yardage dials are also marked in MOA, so I don't know what is lost there. My turret scopes have subtension reticles in them. There are certain advantages to every system. You're got to learn to work with what you have, and eventually you'll learn to not believe anything that you can't prove.

Your CDS scope comes with a free custom dial, so I don't know why you'd not want to get it. You can still use it as a MOA dial if you want, and you still have the original. The custom comes with a zero stop, which is handy with the non ZL because those things spin easily by brushing on clothing and you can't tell by looking at them if you're a full turn or two off. I've posted before on how to put a zero stop on the provided dial, so that's not breaking any new ground.

If you're a hunter who wants to shoot long (600 is a long ways in the field) you might find that your yardage dial is off say 1/2 MOA at 600 from a hundred yard zero due combined errors of BC, scope adjustments, chronograph error, conditions and those ugly little demons that ride on bullets for fun. That can be compensated by sliding your scale until 600 is right, and I think most people would agree that 1/2 MOA error at 100 is a non-issue. Jez; guys sight in 3" high at 100 because they know 3" at a 100 doesn't mean anything. You can tweak your zero a bit with subtension reticles too, to make the long error less and move it back to where the short range error doesn't matter. Don't even get me started on target displacement due to mirage on both the horizontal and vertical planes. My F-class rifles shoot 3 MOA different come ups between my private personal range and the provincial range in mid summer conditions at 1000 yards. So what do you do do with that information? I'll tell you, you shoot. somethings can be tested but the only thing that can be trusted is the target. Even then, while the target doesn't lie its sometimes hard to figure out what its saying.:)

Anyway; lots of ways to skin a cat and if you want to shoot long there are no short-cuts.
 
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Good food for thought dogleg, my intention with this scope is on a switch barrel rifle that is used for both varmint and big game hunting out to around 600 Yards and steel out further at some point. I figured I could use rhs moa turret for one barrel and the custom for the other. Scope is one qd rings and I am hoping I can record clicks to re zero after switching and be pretty close but will obviously have to check dope before hunting. Just a fun project for right now. I'm hoping to cut down on components as well as only having to buy one scope for many different applications. The two chamberings will utilize the same powder as well as primers.
 
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