Home Forums Hunting & Shooting Hunting Optics Leupold CDS elev turrets: report

There are a lot of circumstances where a 100 yd. zero makes sense, for instance-

Africa: Plains game might be at 300 yds, but more likely within 100 yards. A hundred yard zero, especially in brushy country, makes a lot of sense. If the game is small (steenbok, duiker, etc.) precise shot placement on a small target can be important.
Leopard, crocodile: Again, the ability to hold dead on and shoot with precision, at ranges of likely 100 yd. or less, could be critical. If on a multi-species hunt, not having to re-sight in a scope is at least an ammo saver.
Stand hunting: Whitetails, in heavily wooded country, or Texas, hogs and deer over feeders- again, 100 yd. or less may be the most common shot opportunity.

IMO, that 100 yd. zero just makes a flat shooter that much more versatile. Anyway, that's my rationale.

Sounds like you need a base with some elevation built in. Changing from a 100 to a 200 zero is not going to make any difference in the total scope travel that you have.

I run a 100-yd zero on any rifle that gets timber use. It's thick here, the killin' is usually close, and it's not uncommon to have to miss branches etc. That's WAY easier with the 100-yd zero.

(pop quiz: you are running a 2.5" high at 100 zero. Buck is 30 yards away, clear path to the vitals EXCEPT there's a branch bisecting the vitals. Where do you aim?)

But to the point, this point is moot with a normal turret. "Zero" is a floating concept. I like a 100-yd zero for the reasons above, plus it keeps zero setting and verification easy. But up where I hunt elk the timber is thinner and there's openings that allow for longer shots. So... a guy just reaches down, clicks his turret up 8 clicks, and now he's "zeroed" 2" high at 100 yards. His turret reads 2 MOA.

BUT, on a turret where one is limited to one revolution, AND the user can specify to the turret cap maker, if a person wants to max out their useful elevation in that one turn- THEN they can spec to Leup that the 15 MOA of travel starts at a 200-yd zero, rather than 100 yds.

I hope that makes sense. I feel like guys are kind of talking about different things here.

yea, trying to morph turrets and MPBR is silly IMO. the beauty of turrets is that you can dial elevation whenever you wish, so why not do just that? if you want MPBR, just dial it when you leave the truck.

but why set up a rifle so you can dial spot-on @ 775, but not at 100?

Well said- for simple minds like mine, my CDS system, sighted in at a 100 yd. zero, takes me all the way up to 650+ yards with a twist of the turret for the range I want to shoot at, calibrated for the caliber, velocity, and bullet weight etc. I'm using. Simple, simple, simple.

the .8 moa i'd save by going from 100 yard zero to 200 yard zero (7MM WSM/120 NBT) would gain me ~25 yards on the top end (past 800 yds)...

6 of one, half dozen of the other. Zero at 200 and then dial down 1.5MOA if you're hunting thick stuff, or zero at 100 and dial up 1.5MOA if you need max PBR when hunting open terrain...

I think dialing down would melt my brain. But that's just me.

At some point in the recent past, the use of turrets has been elevated to the level of rocket science.

Guessing that for some folks, anything more complex than simply looking thru a scope, and pulling a trigger, is brain strain.....

Turrets aren't hard, but they can be a paradigm shift for some folks, particularly those who like to zero a scope, then not touch it again. I about gave my elk hunting buddies a heart attack at elk camp the night before the season by just grabbing a turret and twisting it (to show them what I meant by using a turret to change elevation).... "You can't mess with that the night before opening day!!"...

It really is a different approach. There is no "zero" in the traditional sense.

If only wind was as easy as elevation. There's the real hurdle to shooting LR.

Because plus or minus two inches is insignificant on a big game (non-crocodile!) hunt, and if you are shooting a Leupold, with one of their excellent reticles (VH, B&C, LRD) it is designed to work best with a 200yd zero. I guess they are stupid also.

Huh????

Another publik skool grajuate.

Ok, I got some things done and some I didn't.

100 yd box test. I hadn't changed my 200 yd zero thus the high POI's. Started lower left, 3 pink hits, moved up 3 MOA/12 clicks = 3 green hits. Move right 3 MOA = 3 blue hits. Moved down 3 MOA = 5 black hits (2 high calls by me). Then back left 3 MOA = 4 orange/black hits. The paper has 1/2" boxes not showing up in pic.

I'm satisfied with the box test.


To be continued.

Alan

Ok, I'm back. Had some "Honey Do's" to do!

As I said earlier, I would re-zero the scope for 100 yds; NOT POSSIBLE! The way Leupold built the scope, I can't zero it for 100 yds. Here, I'll show you.

When the dial is removed, their is a small, upward protrusion as part of the elev housing. It's just above the small white line at the 6-o'clock position of the elev housing.





Then, when looking at the underneath side of the dial, their is a small steel bearing, implanted in the ceiling of the dial that butt's up against the small steel upright of the elev housing as it spins around. Thus, a 100 yd zero is not possible. In fact, when I get a 200 yd zero, verified again today, I barely have enough room to the get 200 yd zero. I can only go about 1/2 click below 200.




[img]http://i26.photobucket.com/albums/c129/GSSP/Pre%2064%20M70%2093x62/IMG_20110416_181926.jpg[/img]

Now, I was running out of time as I had to get home for the Honey Do list.

I put several shots on paper at 300 and 400.


For those wondering. I was chronographing over my Oehler 35P. 20 shots = 2604 fps with 31 ES and 8 SD so dial should line up with the data I gave Leupold.

But.....

When I tried to put it on my 15" wide x 27" high LV Steel silhouette @ 500 yds, not a hit. As I didn't have a spotter with me, and with the attenuating recoil, their was no way I could spot my own misses. I kept dialing up 1 click at a time until I ran out of ammo; Nothing, Nada, Nine, hits! I have a large, 4' x 3' card board backer but didn't have time to set it up before having to head home.

So, again, I'm very confident, I can get hits to 400. Beyond??????

Alan

PS,

Had some great scenary this am. Zero wind when shooting the 100 yd box.

that is the zero stop. the original moa knob probably doesn't have the zero stop (none of mine do), but the custom ordered knobs all seem to.

do you still have the moa knob?

i don't have a 9.3, but my .375 AI will get from 100 to ~600 with 15 moa

Toad,

I do have the original MOA knob. If this rifle were chambered in a LR caliber, or at least a caliper that I could use out to say 600 yds, I'd use the MOA know but the ballistics of a 250 AB in 9.3x62 are not super flat.

I'll work on it some more and get the drop at least out to the upper end of the zero stop.

Alan

Update.

I took a break for a bit while working on another rifle. Couple of Saturday's back I decided to give it one more try. I checked my 200 yd zero and it was on. I then put up a 400 yd target. The plan was to place a group on target, then if necessary, walk my elev knob up so that I would get my group centered and see where the elev turret ended up.

The first shots are the ones marked in red, 5" below center. Wind from my 6 with quite a bit of boil. With 6x mirage was quite evident.


I then started working my way up. One click @ 400 should move me 1". So, 5 clicks up and I get some movement upward but not the 5" I expected. I add a few more clicks and still not centered. One or two more and I get the two shown in the little rectangle. I now realize something is wrong. I should now, be hitting higher than the red bullseye and yet I'm not. I decide to stop since 250 Accubonds are not exactly cheap to buy.

At home I put my Leupold magnetic boresighting device on and from a 200 yd zero watch the reticle move downward, as it should. But when I get to about 300 yds on the dial, the reticle ceases to continue to move down. Even when I max out over 500 yds on the dial, the reticle has not moved since I passed the 300 yd mark on the elev dial.

The scope has 45 MOA of elev travel. The scope is in appropriate Leupold QR bases/rings on the Pre 64 M70 action. I figure that maybe with a 200 yd zero I'm near the end of it's elev travel and beyond 300 I'm at the end. I contact Sean, the same tech @ Leupold. He agrees that I've done all I can do and emails me a prepaid UPS shipping label. I offer to try shimming the base but he politely tells me that I've done everything within reason a shooter/owner can do and it's time for Leupold to take it from here. Kudo's for Leupold. It went out yesterday and I will patiently await to hear back from Sean.

His last quote....

"Due to time and ammunition cost I would like to have the scope in to us and run through a few shooting/adjustment drills."

Alan

Aargh. I want a CDS Leup but I've seen enough chattery tracking over the years to be somewhat suspicious. Then again I have an older 2.5-8 that track beautifully.