Rifle Scopes S&B question on zeroing and max elevation...

cali_tz

cali_tz

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Oct 4, 2010
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#1
with my S&B PMII 25x scope zero'd at 100 yards, I can dial up the scope elevation turret twice around, up to like 68 or 69 MOA up. I forget the exact number, but there seems to be a hard stop there. Probably because there is no way to know if you are doing around the third time, for you S&B PMII owners, you know what I am talking about.

Problem is given my particular ballistics 68 or 69 MOA doesn't get me out past 1700 yards. I have to hold higher using the reticle, which I can do, but I'd prefer to have the crosshair on the target instead for the nominal range elevation.

Question: if I zero the rifle for like 300 yards (instead of 100), what happens... will be able to go all the way up again 68-69 MOA which should get me out to 2000 yards hopefully? Or will the elevation adjustment stop before I go all the way around twice?

My other option is to put a 20MOA ring/base on top of the existing 20MOA base and get 40MOA, but that comes from only one place in the world, MAK in Germany, and they don't answer emails.

thx for your advice.
 
#3
Re: S&B question on zeroing and max elevation...

Thanks LL... the docs seemed to suggest it was designed for a 20MOA base, but a 45 would make more sense for my 338LM, otherwise a 20MOA scope leaves this thing topped out at 1600 yards at best.

Does anyone know of a 34mm ring set that comes as part of a 20MOA (or so) picatinny mountable assy? The MAK Mil Mount does the trick, but those guys seem permanently offline.
 
#7
Re: S&B question on zeroing and max elevation...

the Barrett ExRings seem perfect for what i need to do. Selectable for either 20 or 30 MOA... I can try both over time. Thanks gents... great recommendations.
I assume Barrett is as heavy duty and rigid a solution as would be the Spuhr, which itself looks like a Panzer tank.
 
#9
Re: S&B question on zeroing and max elevation...

Might want to call s&b customer service. You should be getting more vertical travel out of your scope unless I am mistaken. Kick ass scope though.
 
#10
Re: S&B question on zeroing and max elevation...

steelshot, you really can't or shouldn't get more than two full revolutions of the turret.. that's their system unlike my Leupold 25X which can keep turning revolutions past two (it has that little tree for figuring out where you are). With the S&B on the first turn the turret top is in black, on the second turn you are in yellow at the turret top, and hence there is no third revolution of the turret under this design. That gives you like 68 +/- MOA total.

This is as far as I understand the S&B hw, reading the manual and playing with the zeroing process. But even the manual is confusing saying there is only 56MOA of adjustment. Strange.
 
#11
Re: S&B question on zeroing and max elevation...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">Thanks LL... the docs seemed to suggest it was designed for a 20MOA base, but a 45 would make more sense for my 338LM, otherwise a 20MOA scope leaves this thing topped out at 1600 yards at best.</div></div>
<span style="font-weight: bold"><span style="font-style: italic">cali_tz</span></span>: You need to read the documentation more carefully - <span style="font-weight: bold">PMIIs' are designed and engineered to be used with aggressively canted bases. PMII variables' are preset at the S & B factory with their reticles' adjusted out-of-center by HALF of their FULL Elevation travel, giving them UPWARD Elevation bias. In order to compensate for this mechanical bias/offset, a base that approximates one half of each respective scope's full Elevation travel should be used.</span> <span style="font-weight: bold"><span style="font-style: italic">(Which, for a non-Locking Turret .25 MOA PMII 5-25X is 65 MOA)</span>.</span> <span style="font-style: italic">Theorietically</span>, you want a 32.5 MOA base. However, its' a good idea to get a base with a few "extra" MOA built-in to allow for the 5-7 MOA you'll probably use to zero at 100 yards. Now you're at a 38-40 MOA base. The 0.1 MIL version of the PMII 5-25X was originally designed to be used on a 45 MOA base and the .338 LM. You should also be able to use a 45 MOA base as well. Schmidt Bender only developed the .25 MOA version under pressure from the U.S..

Selection of a base with the correct cant is all detailed in the <span style="font-weight: bold"><span style="font-style: italic">"2006 PMII User Manual"</span></span> beginning on page 3 under <span style="font-weight: bold"><span style="font-style: italic">"Section 4.2"</span></span>, <span style="font-weight: bold"><span style="font-style: italic">"Adjustment range and forward angle"</span></span> and concluding on page 4. Italicized and in quotation marks below is the section I am speaking of. Below the text of Section 4.2 is a diagram from page 19 of the PMII User Manual showing <span style="font-style: italic">"picture 2"</span>, <span style="font-style: italic">"picture 3"</span>, and <span style="font-style: italic">"picture 4"</span> as referenced in the (2006) User Manual. Keep in mind that the Manual does not allow for any travel used to "zero" the scope as I did in my paragraph above.

<span style="font-weight: bold"><span style="font-style: italic">"4.2. Adjustment range and forward angle

Scopes for high precision shooting are often used for shooting at great
distances. In this case the elevation adjustment is used to compensate for bullet
drop. To provide an extensive elevation range in these scopes Schmidt &
Bender has increased the main tube diameter from 30mm to 34mm.
Nevertheless the elevation and windage range like in any other scope is limited.

In scopes for hunting the reticle is generally centered optically and mechanically
in order to receive the same amount of travel in all directions and to make the
mounting of the scope to the firearm easier (see picture 2).

In order to make the elevation adjustment range usable in its full extent it is
necessary to preset the reticle of the PMII scopes out of the center already at
the Schmidt & Bender factory (see picture 3). As a consequence the gunsmith
is obliged to consider the preset position of the reticle in the elevation range
when mounting the scope to the firearm (see picture 4). With this setup the full
elevation range is usable in one direction allowing to shoot at distances up to
2000m depending on the used calibre and scope type.

Determining the correct forward angle
The necessary forward angle is depending on the used type of elevation
adjustment. At the Schmidt & Bender factory the reticles of PMII scopes are
adjusted out of center by half the amount of the full elevation range. This value
must be compensated in the mount system.
Forward angled mounts or rails for every Schmidt & Bender PMII scope type
are available from all renowned mount manufacturers.

Example for determining the required forward angle:
A standard elevation turret (Single Turn) with an elevation range of 13mrad
(equals 130cm at 100m distance) requires a forward angle of 65cm at 100m
(equalling the half of the full elevation range). For a gunsmith compensating for
this value using the mounts the following rule of thumb applies: If the space
between the two mount rings is 100mm the front mount should be 0.65mm
lower than the rear mount.

If the gunsmith is using a forward angled rail standard mount rings without
forward angled can be used."</span></span>

<span style="font-weight: bold"><span style="font-style: italic">"picture 2"</span>, <span style="font-style: italic">"picture 3"</span>, and <span style="font-style: italic">"picture 4"</span> as referenced in the <span style="font-style: italic">2006 PMII User Manual:</span></span>
SBPictures800x531.jpg



I hope this post clears-up any confusion members may have about the use of canted bases and the correct base cant for use with PMIIs', as well as to help guide new PMII owners' and would-be PMII owners' towards the selection of the correct base for use with their PMII.


<span style="font-weight: bold"><span style="text-decoration: underline">NOTE:</span></span> <span style="font-weight: bold"><span style="font-style: italic">In the diagram above:</span></span>

<span style="font-weight: bold">"<span style="color: #FF0000">Picture 2</span>"</span> shows a scope mounted on a rifle with a flat (non-canted base). The drawing illustrates a typical scope with optically-centered reticle and erector. Personally, I always use canted bases, as they have no downside - they dont adversely affect 100 yard zeroing and shift a bit of Elevation travel to the upper end of the scope's adjustment range.

<span style="font-weight: bold">"<span style="color: #FF0000">Picture 3</span>"</span> shows a scope mounted on a rifle with a flat (non-canted base). The drawing illustrates the effect that the PMII's Reticle offset (PMII reticle's are preset at the factory <span style="text-decoration: underline">biased towards the top of the scope tube</span>) has upon the PMII's operation and the PMII's requirement for specific cant scope bases. This mechanical offset is engineered into the PMIIs' and requires use of specific cant bases in order to get optimum Elevation travel out of respective PMII scopes. The Reticle's off-center orientation (towards the top of the tube) means that you're actually looking very slightly upward when you look through a PMII at the bottom of it's travel, and that the Reticle's LOS (Line-of-Sight) won't intersect the projectile's trajectory without a lot of "UP" adjustment. Obviously, the scope's offset over the bore will require the shooter to use a lot of "UP" adjustment to zero the rifle. Use of a correct cant base eliminates these issues and allows the PMII to function as designed.

<span style="font-weight: bold">"<span style="color: #FF0000">Picture 4</span>"</span> shows a scope mounted on a rifle with a canted base. The drawing illustrates how the use of a base with the correct cant affects the PMII Reticle's LOS (Line-of-Sight) and allows the respective PMII access to it's full Elevation adjustment range. The Reticle is still oriented at the top of the scope tube, but the canted base has angled the scope (and Reticle) slightly downward in relation to the axis of the bore, allowing the Reticle's LOS (Line-of-Sight) to intersect with the projectile's trajectory. The scope can now be "zeroed" with minimal Elevation adjustment. After the scope is zeroed, the Elevation Turret shoud be set to "0". Scopes with DT (Double Turn) Elevation Turrets should be reset.

Also, the illustrations show the bullets arcing upward from the axis of the bores. This, of course - does not occur in real life. I'm sure that the gravity-defying bullets were drawn in that manner to simulate the arc of the rounds as they travel downrange.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">Does anyone know of a 34mm ring set that comes as part of a 20MOA (or so) picatinny mountable assy? The MAK Mil Mount does the trick, but those guys seem permanently offline. </div></div>
I recommend that you use a mount or base that has 40-45 MOA of cant (allowing you to be able to get the most travel out of your scope). Aside from the SPUHR, NEAR Alpha Mount you can also use a one or two-piece base. I use a Tac Ops 40 MOA Two-Piece base on my Tac Ops X-Ray 51, but I may switch over to Tac Ops 45 MOA Two-Piece Base just to squeeze the last bit of Elevation travel out of the scope. Both the 40 and 45 MOA Tac Ops Bases are drilled for 8-40 screws.

<span style="font-weight: bold"><span style="font-style: italic">Tac Ops X-Ray 51 in "Tac Ops OD" with PMII 5-25X 0.1 MIL Gen 2 XR CCW, Tac Ops 40 MOA Two-Piece Base, & Leupold Mark 4 High Rings:</span></span>
X-Ray51BT28RSProfileFF18x6.jpg



Keith
 
#12
Re: S&B question on zeroing and max elevation...

In the first post cali tz says he has 68 moa of "up" available with his current setup. Aries64 posted the user manual saying there is 65 moa total elevation available according to S&B. Sounds like cali tz is getting everything he can out of the scope right now??
 
#13
Re: S&B question on zeroing and max elevation...

Keith, it's not that I didn't read the S&B docs carefully... it's just that I didn't understand it. Thanks to your explanations of the pics (which didn't make sense to me in the manual) I now finally get it. I don't know why, but optical theory is simply not intuitive to me. <thank you for taking the time to explain this carefully!>

May I ask then why does Steyr ship their 338LMs from the factory with only a 20MOA base? You're right that the S&B manual says nothing about using a 20MOA base. I then must have read it somewhere, maybe in the Steyr manual or somewhere where it said that a 20MOA base with the S&B PMII 5x25 was the right combo.

Oh well, as I found out, and as you state, 20MOA is not enough if we're going farther to a mile. Keith, do you have a problem with the Barrett exRings? They look like a great solution to this issue?

Also do you think that the max internal travel of the S&B PMII 5x25 is actually the 65 or 68 MOA that the two turn turret gives you, or is there more than that built in?
 
#14
Re: S&B question on zeroing and max elevation...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">Keith, it's not that I didn't read the S&B docs carefully... it's just that I didn't understand it. Thanks to your explanations of the pics (which didn't make sense to me in the manual) I now finally get it. I don't know why, but optical theory is simply not intuitive to me. <thank you for taking the time to explain this carefully!></div></div>
No problem, Tony. I apologize for any offense if taken. I wrote up that explanation of the diagram because it can be somewhat confusing - not two weeks ago a friend of mine who owns a Hensoldt asked about canted base use with PMIIs' and how the diagrams correlate to the mechanics. I consider him to be pretty sharp, but he couldn't get his head wrapped around the mechanics either until we spoke on the phone while referencing the diagram so don't feel bad.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">May I ask then why does Steyr ship their 338LMs from the factory with only a 20MOA base? You're right that the S&B manual says nothing about using a 20MOA base. I then must have read it somewhere, maybe in the Steyr manual or somewhere where it said that a 20MOA base with the S&B PMII 5x25 was the right combo.</div></div>
I have no experience with the Steyr .338 LM nor have I read any documentation on it. Maybe you read something about a 20 MOA base in the Steyr Manual, but you may have also read about people using 20 MOA bases with PMII 5-25X, PMII -4-16Xs', and/or PMII 3-12Xs' here on the SH or other shooters' forums, which people often do. Do 20 MOA bases work? Sure they do - but most people including myself rarely, if ever - have occasion to have to dial all the way up. However, the bottom line is that although people often use 20 MOA bases with PMII 5-25Xs' 20 MOA isn't the correct cant for use with the PMI 5-25X, regardless of the caliber of the rifle the scope is mounted on.

For instance, the .308 Winchester is the most common and widespread round people shoot, and efficient .308 loads will perform well out to 1,000 yards just about anywhere in the U.S. and be dialed-on within less than a single turn of a 0.1 MIL PMII. So, a 20 MOA scope will get most shooters as far as they are going to shoot and then some. However, in order to be able get maximum travel out of a PMII (and thus use it more efficiently) the proper cant base should be used. In the case of a .338 LM you really need the right cant. Personally, I prefer MIL over MOA. The 0.1 MIL version PMII 5-25X also has much more travel than the .25 MOA version does.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">Oh well, as I found out, and as you state, 20MOA is not enough if we're going farther to a mile. Keith, do you have a problem with the Barrett exRings? They look like a great solution to this issue?</div></div>
Nothing against them at all. I just haven't seen them in actual use or even mounted at the ranges I shoot at. But that doesn't mean anythng.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">Also do you think that the max internal travel of the S&B PMII 5x25 is actually the 65 or 68 MOA that the two turn turret gives you, or is there more than that built in? </div></div>
I don't know what the <span style="font-style: italic">internal</span> travel is, but S & B specifies 65 MOA Elevation adjustment so that is really about what you should have. However, there is typically a bit of variation from unit to unit. Not enough to worry about - if anything there seems to typically be a bit of "extra" adjustment. I also want to point-out that at the extreme ends of the adjustment range its' possible to turn a turret and hear a "click" without reticle movement being observed as you look through the scope using a collimator or other device such as a Leupold Zero Point. This phenomenon isn't directed towards any particular manufacturer, it is a general observation (no pun intended). Have you tried observing the reticle movement at the far ends of the adjustment range while using the afore-mentioned collimator or Leupold Zero Point to see if the reticle with every last "click"? If you have and you have 68 or 69 MOA (three or four more MOA than specified by S & B) and they reticle moves with each click thats' great.

Also, in your OP (original post) you asked <span style="font-style: italic">"if I zero the rifle for like 300 yards (instead of 100), what happens... will be able to go all the way up again 68-69 MOA which should get me out to 2000 yards hopefully? Or will the elevation adjustment stop before I go all the way around twice?"</span>. I don't have any .25 MOA version PMIIs', but PMII DT Elevation Turrets can be reset after zeroing. You should be able to zero at 300 yards, then loosen the dial set screws and reset the DT Elevation Turret by spinning the Elevation dial two revolutions opposite the direction of "UP", then pushing the Elevation Turret back down and aligning the "0" on the Elevation Turret with the index "triangle" on the scope body. However, you defintely should use a 40-45 MOA base cant. Even better would be to use a 40-45 MOA base in conjunction with a 0.1 MIL version PMII 5-25X for an Elevation adjustment range better suited for the capabilities of the .338 LM.


Keith
 
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#15
Re: S&B question on zeroing and max elevation...

Keith, thank you very much for the precise explanation. Very helpful. Well I got the MOA based scope because that's how I was taught to shoot and I think in inches and feet and yards when estimating the correction. I did NOT know that the MIL reticle had more adjustment, but it makes sense that the 1/4 MOA would eat up the 2X revolutions with less overall elevation accomplished. Crap. I really wish that had been spelled out more clearly. I haven't seen others talk about that.

On your last paragraph above, and thanks for getting back to my question, the preference for using a 40-45MOA base, versus resetting the zero from 100yds to (say) 300 yards, is that with the 40-45MOA base the optics are in a 'sweeter' spot than if I was hitting the edge of the actual mechanical elevation capability, right?

Last question... with this 40-45MOA base then, I won't be able to have scope zero at 100 yards and also be able to use the reticle crosshairs at 2000 yards.. because the 65 MOA just won't get there. So I'll have to zero at more like 300-400 yards, right?
 
#16
Re: S&B question on zeroing and max elevation...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">Keith, thank you very much for the precise explanation. Very helpful. Well I got the MOA based scope because that's how I was taught to shoot and I think in inches and feet and yards when estimating the correction.</div></div>
Again, no problem. I tend to read a lot more than I post, but if see a question that hasn't been addressed or hasn't been correctly answered, and if I happen to know the answer(s), and if I have time to post I usually will. Sometimes I just don't feel like it.

That said, I was born and raised in L.A. so like you I'm used to Imperial measurements and weights. When I estimate lengths and distances I think in inches, feet, yards, or miles - not centimeters, decimeters, meters, or kilometers. But you know what? None of that matters because the only thing all those units have in common is that they're all linear measurements. INCHES ARE NOT MOA AND CENTIMETERS ARE NOT MIL. MOA and MIL are angular units of measure.

If I may be so bold, you and a lot of others shooters make it hard on yourselves and bake your brains over nothing. Once you have an accurate load you need an accurate chronograph and a weather meter so you can get accurate muzzle velocity and environmental data to input into JBM or another good ballistic program to make data cards for the locations you shoot at. As long as you plug in accurate Muzzle Velocity, Drag Coefficient, altitude, and pressure your range card(s) should be very close for that particular shooting location and load. Temperature and humidty do affect the outcome so accurate info there is desirable, but they have a lot less effect than velocity and drag coefficient. The more you shoot the more you'll remember the adjustments necessary for a given distance, wind, ect.

I still estimate in yards, but when I need to adjust my MIL-based scope I hold or dial the Elevation based on my estimation. If I don't know or remember the required adjustment I just look at my data card. And if I am off I see the POI and either dial or hold the appropriate adjustment(s).

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">I did NOT know that the MIL reticle had more adjustment, but it makes sense that the 1/4 MOA would eat up the 2X revolutions with less overall elevation accomplished. Crap. I really wish that had been spelled out more clearly. I haven't seen others talk about that.</div></div>
Tony, the reason the MIL-based version of the PMII 5-25X has greater adjustment range is that a 0.1 MIL (.36000") is more coarse than .25 MOA (.26175"). Because each "click" of a 0.1 MIL adjustment moves the reticle a greater amount, the overall adjustment of the MIL-based PMII 5-25X is greater than that of the MOA-based version.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">On your last paragraph above, and thanks for getting back to my question, the preference for using a 40-45MOA base, versus resetting the zero from 100yds to (say) 300 yards, is that with the 40-45MOA base the optics are in a 'sweeter' spot than if I was hitting the edge of the actual mechanical elevation capability, right?</div></div>
On a PMII the zero distance is not the determining factor for determining the base cant - the mechanical offset of the reticle is the determining factor. While a 40-45 MOA base puts the reticle in the "sweet spot" on a PMII 5-25X, you should be using a 40-45 MOA base regardless of whether you zero at 100 yards or 300 yards.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">Last question... with this 40-45MOA base then, I won't be able to have scope zero at 100 yards and also be able to use the reticle crosshairs at 2000 yards.. because the 65 MOA just won't get there. So I'll have to zero at more like 300-400 yards, right? </div></div>
I don't know the ballistics of your round, but think about it - if it takes more than 65 MOA from a 100 yard zero to center the reticle on the target for a dead-on hold, the answer is "NO". You'd have to zero further-out, then reset your Elevation Turret so you can dial maximum adjustment to get there.

Personally, I would suck it up and sell the MOA-based PMII and buy a MIL-based version. My favorites are the Gen 2 XR, P4F, and MSR reticles. The Gen 2 XR would have to be bought used, is harder-to-find, and demands a premium if a Seller knows what they have but is better for smaller targets. The P4F's line widths are just a bit thicker than the Gen 2 XR and is easier to MIL objects more finely. The MSR has slightly thicker line widths than the P4F and considerably thicker line widths than the Gen 2 XR, but it's extra MIL scale is easier to range accurately with as well as being easier to see because it is more coarse than both the Gen 2 XR and the P4F. For me, the tradeoff of the thicker reticle lines isn't an issue as the thicker lines will be less of a hinderance to bullet placement than the environment is at the distances a .338 LM would be shot.


Keith
 
#17
Re: S&B question on zeroing and max elevation...

Keith, your patience and thorough explanations are much appreciated, thanks. It's posts like these that make snipershide a real service to the community.

I understand what you are saying. So I think I take the following steps:
1) get a total of 40-45MOA of cant via adding a 20-25 ring/mount solution to my existing 20MOA scope picatinny base.
2) zero at >> 100 yards in order for 65MOA (I will try your Leupold collimator test, i have the unit, to see how many of those last clicks actually move the erector) to line the crosshairs at 1750 yards, for example. My ballistics calc can easily figure out where my zero should be for this to happen. It's silly to shoot the 338LM at distances less than 300 anyway, so I won't be losing anything that I use today.
3) for extra credit get the 0.1mil adjustment (elevation) S&B PMII, as it naturally builds in more elevation for the double turn turret. I think quarter MOA is a silly elevation adjustment so far in my short ELR shooting career. I would have easily been happy with 0.5MOA and more elevation range, and just hold and up down from there. My ballistics calc does give me elevation adjustments to one decimal precision, but I just round to the nearest quarter and it's close enough for one MOA.
 
#18
Re: S&B question on zeroing and max elevation...

one last thing on MOA vs MILS on the elevation. MILS on the reticle is great, for milling the target, we learned that, practiced that, but I am investing in a good range finder. But milling is a good backup.

For MOA on the turrets, we sort of know the size of the target and we grew up estimating size in inches/feet/yards... so estimating the correction in in/ft/yd is quite fast, and conversion to MOA quite fast since we approx give 1" to 1MOA per 100 yards.

If I have all that straight, then how can you so quickly call for an adjustment in MILS ... do you size up the correction in in/ft/yds and then convert the total to MILS by knowing that a MIL at 1000 yards = 36" or something like that?

In the end, you're right though. Since the reticle is in MILS, and I'd rather implement the correction by holding over with the MIL reticle rather than twirling the knobs and taking my eye off the scope. I think you've got me convinced.
 
#19
Re: S&B question on zeroing and max elevation...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">
I assume Barrett is as heavy duty and rigid a solution as would be the Spuhr, which itself looks like a Panzer tank. </div></div>

I don't think any two piece ring set is going to be as rigid as a one piece like the Spuhr, but the Barrett rings are plenty stout. I use them to mount an S&B 5-25x56 on my .50 BMG. No issues.
 
#20
Re: S&B question on zeroing and max elevation...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">one last thing on MOA vs MILS on the elevation. MILS on the reticle is great, for milling the target, we learned that, practiced that, but I am investing in a good range finder. But milling is a good backup.

For MOA on the turrets, we sort of know the size of the target and we grew up estimating size in inches/feet/yards... so estimating the correction in in/ft/yd is quite fast, and conversion to MOA quite fast since we approx give 1" to 1MOA per 100 yards.</div></div>
As far as scope adjustments go, I understand the desire to use a unit of measure (MOA) that <span style="font-style: italic">seems</span> similar to Imperial (Inch), but they are entirely different. I may be wrong, but I think that one of the main reasons that MOA-based adjustments were originally mated with the Mildot reticle was for "simplicity". MOA-based adjustments were the predominant turret increment in the States, an MOA was pretty close to an inch at the 100 yards, and the milradian was already being used by the military in tanks and for artillery solutions.

The desire to use a unit of measure that <span style="font-style: italic">seems</span> similar/familiar to U.S. personnel is understandable, but in the process the U.S. Government shot them in the head (mind-fu<king them) by mixing the Mildot reticle with MOA-based adjustments. Hence the requirement to convert from MIL to MOA if corrections were to be <span style="font-style: italic">dialed</span> rather than held. The more logical (but more expensive and time-consuming approach) would have been to develop MIL-based turrets. That would have required completely new turrets and the tooling to cut the gears, possibly new scope bodies. Ugh.

The other alternative would have been to develop MOA-based reticles so that the reticle and turret systems would match. That would have been fine as no conversion would be required before dialing corrections. But I guess that made too much sense to the Gov't too. I think that it would have been better to go all MIL at the time, since artillery and tanks were already using MIL. Unfortunately and historically the U.S. Gov't. has usually gone with what <span style="font-style: italic">seemed</span> to be the most expedient, lowest cost solution at the time.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">If I have all that straight, then how can you so quickly call for an adjustment in MILS ... do you size up the correction in in/ft/yds and then convert the total to MILS by knowing that a MIL at 1000 yards = 36" or something like that?</div></div>
Thats' why its' so important to have matching reticle and adjustments - either MOA/MOA or MIL/MIL. Whether you're shooting or observing your reticle is your scale, so you make or call any needed correction(s) based on what you see through the scope. Obviously, if you hold the correction(s) the reticle and turrets don't have to match, <span style="font-weight: bold"><span style="font-style: italic">but if you dial the correction(s) they should match unless you like doing conversions</span></span>.

IF YOU'RE CONVERTING TO INCHES IN ORDER TO DETERMINE DROP TO MAKE CORRECTIONS WHILE SHOOTING YOU'RE DOING IT WRONG. I have a friend that I met just about the time I bought my first high end scope (a MIL/MIL USO SN-3 Lo Pro ERGO). My friend liked my USO, and decided to buy one in MOA/MOA. This would also be my friend's first high end scope and I tried to get him to go MIL, as I had just switched to MIL and I wanted us to be able spot for and call for each other in the same system. He refused, saying that <span style="font-style: italic">"he couldn't get his head wrapped-around <span style="font-weight: bold">MILs'</span> and that MOA was easier to use"</span>. I didn't press him at the time, figuring it was his money and if he was comfortable with MOA I'd let him be.

However, as we began to shoot together and call for each other the PITA of using two different systems just wore on me, so I again tried to get him to switch to MIL. He steadfastly refused, and this continued until last year when I asked him what makes MOA easier for him to use. He told me that he <span style="font-style: italic">"thinks in inches"</span> and that he could <span style="font-style: italic">"estimate corrections in inches and convert corrections to MOA easier than he could convert the correction to MILs'".</span> I thought <span style="font-style: italic">What? Who cares what the drop or correction is in inches - it doesn't matter. Inches are linear measurements that have nothing to do with MOA. You just dial or hold whatever correction you need based upon what you see through the scope.</span>

It was only then that I realized that my friend wasn't using his scope as it was intended to be used. All this time he'd been using MOA as a crutch, complicating things that are so simple. It took him a long time to grasp the practical difference between angular and linear measurements, but once he "got it" he decided that he should learn both systems. Looking through the PMII 5-25X 0.1 MIL CCW Gen 2 XR on my X-Ray 51 my friend became interested in the PMII 5-25X 0.1 MIL CCW Gen 2 XR. Unfortunately, hes' a lefty and as you know the tube-mounted illumination control on PMIIs' can interfere with bolt operation on LH actions. Wanting a MIL scope and needing one that he could mount on his lefty Tac Ops X-Ray 51 I test-fit one of my PMII 5-25Xs' on his rifle before the action was sent to Birdsong for coating. The bolt knob cleared the PMII's illumination turret but my friend bought a Premier 5-25X MTC DT Gen 2 XR (also a very nice scope).

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cali_tz</div><div class="ubbcode-body">In the end, you're right though. Since the reticle is in MILS, and I'd rather implement the correction by holding over with the MIL reticle rather than twirling the knobs and taking my eye off the scope. I think you've got me convinced. </div></div>
Since you prefer to hold corrections instead of dialing them, the mis-matched MIL reticle/.25 MOA turrets don't matter. Problems only arise if you make corrections by dialing without converting the MIL-based correction needed to MOA before dialing-in the correction(s) - (the reticle is MIL-based but you're dialing in MOA increments). Still better to have matching reticle and turrets though - that way you can dial without having to convert.

If you do decide to buy a new PMII and want to dial corrections without looking you should check-out the PMIIs' with MTC (More Tacile Click) Turrets. Some people like them, some people hate them. As you may have read the main complaint is that is is difficult to dial to 0.1 or 0.2 past a "full" MIL (The MTC Turrets have a heavy detent at each MIL, and getting past the heavy detents' requires a bit of extra effort to turn the these detents, resulting in people slightly over-spinning the Knob by 0.1 or 0.2.

The MTC turrets that I've had the pleasure of playing with (on USO, Premier, and PMII scopes) seem a bit tight when new <span style="font-style: italic">(isn't everything)?</span> This was also my experience with the MTC-equipped PMIIs' at SHOT 2011. This, coupled with shooters who typically aren't used to using MTC turrets is - IMHO - one of the reasons some people complain about spinning past their intended adjustment by a click or two. I have a friend who has a PMII 5-25X MTC and used to spin past the first tenth every time but once he got used to the MTC he stopped "over-dialing" his adjustments. I believe that as the scope is "broken-in" and/or as the shooter becomes accustomed to the MTC turrets the "over-dial problem" should go away. <span style="font-weight: bold"><span style="font-style: italic">That said, TRY BEFORE YOU BUY!</span></span>


Keith
 
#22
Re: S&B question on zeroing and max elevation...

thanks all, critical and helpful info. There ought to be a forum where the experts help gun owners new to a caliber or shooting application build their rifle correctly from the get go. I've made a few incorrect choices along the way which could have been easily pointed out early in the process.
 
#23
Re: S&B question on zeroing and max elevation...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bhanDallas</div><div class="ubbcode-body">Badger makes a 45 MOA rail as well. I think that Steve over at triad has them in stock. I was looking at them yesterday. </div></div>

I don't want to mess with replacing the scope base... it's on their nicely. I would much rather get a rings solution that adds the addtil required MOA. That's more a bolt on solution and I don't have to deal with what could possibly be nicely Loctite'd in base screws.
 
#24
Re: S&B question on zeroing and max elevation...

Does anyone know what moa base I would need for s&b scope with 13 mrads total elevation?
 
#25
Re: S&B question on zeroing and max elevation...

I have read Keith's explanation as well as factory manual which are the same. I have a 4-16x50 PMII double turn and no way can I get a 100 yard zero with a Near 45 MOA base, Badger zero rings on a TRG I lack 6+ MOA @ 100. I'm getting the full 56+ MOA of adjustment it just ain't happening with mine. Am I missing something?
 
#26
Re: S&B question on zeroing and max elevation...

The single turns work with a 20 MOA base. It's what i used with my two 4-16x PMIIs. The 45 MOA is used with the higher internal travel 5-25x PMII.
 
#27
Re: S&B question on zeroing and max elevation...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ruth</div><div class="ubbcode-body">Does anyone know what moa base I would need for s&b scope with 13 mrads total elevation? </div></div>
A 28-30 MOA base would be ideal, but a 20 MOA base will also work (you'll probably be around 2.8 MILs' shy of the full [13 MILs'] of travel once you're zeroed, but it isn't a huge deal unless you need access to the full range of travel). I prefer to use the correct base whether I can make use of the full Elevation range or not.


Keith
 
#28
Re: S&B question on zeroing and max elevation...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mark S</div><div class="ubbcode-body">I have read Keith's explanation as well as factory manual which are the same. I have a 4-16x50 PMII double turn and no way can I get a 100 yard zero with a Near 45 MOA base, Badger zero rings on a TRG I lack 6+ MOA @ 100. I'm getting the full 56+ MOA of adjustment it just ain't happening with mine. Am I missing something? </div></div>
If you're using a 45 MOA base with a PMII 4-16X DT you're using the wrong base. Its' really very simple. As explained in the PMII User Manual <span style="font-weight: bold"><span style="color: #FF0000">the correct cant for a PMII is one that approximates one half of the total Elevation travel of the scope</span>.</span> <span style="font-weight: bold">A PMII 4-16X DT has 56 MOA, so 28 MOA</span> - <span style="font-weight: bold"><span style="text-decoration: underline">NOT 45 MOA</span></span> is the correct cant.

A 28 MOA cant does not allow for any "UP" adjustment that you'll use while zeroing (approximately 5-7 MOA), so in reality you could probably use a cant of 33-35 MOA and still get a perfect 100 yard zero.


Keith
 
#30
Re: S&B question on zeroing and max elevation...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mark S</div><div class="ubbcode-body">I FINALLY got it Keith. A 45 would not work on 5-25x56 PMll MOA either because it has same 56 MOA range. </div></div>
NO dude, you still don't <span style="font-style: italic">"get it"</span>. A 45 MOA base CAN work with the MOA-based version of the PMII 5-25X56. <span style="font-weight: bold"><span style="text-decoration: underline">(a) The PMII 5-25X56 has 65 MOA of Elevation travel, NOT 56 MOA.</span> (b) The optimal base cant for the MOA-based PMII 5-25X56 (which has 65 MOA of Elevation travel), is 40 MOA, and since a 45 MOA base only has 5 MOA (about 1.4 MILs') more than a 40 MOA base it should work fine.</span>


Keith
 
#32
Re: S&B question on zeroing and max elevation...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mark S</div><div class="ubbcode-body">Keith, Europtic and other's that sell the 5-25x56 show total adjustmant of 56. If they had shown 65 I would have figured it out, I DO get it. </div></div>
Don't feel too bad - you assumed that the info on EuroOptic's web site is accurate. And there are probably other S & B dealers that also list the .25 MOA version of the PMII 5-25X56 with the same info. Those dealers probably also got their info from the Schmidt Bender USA web site. Schmidt Bender USA's PMII web page states <span style="font-style: italic">"The 5–25 x 56 is offered with 56 MOA of 1/4 MOA clicks, or 273cm (93 MOA) of 1cm clicks. Your choice of P3 or P4 reticles."</span>

Schmidt & Bender really should correct the erroneous information about the travel of the .25 MOA version of the PMII 5-25 on the S & B USA web site, as well as update the information to include all of the available reticles and scopes. I read one or two other mistakes on the S & B web site a while back too.

Below are two (2) photos I got off of <span style="font-weight: bold"><span style="font-style: italic">euroOptic's Schmidt Bender PMII 5-25x56 L/P P4 Fine MOA Reticle DT 1/4 MOA CCW Turret</span></span> page. The Main Photo displayed on the <span style="font-weight: bold"><span style="font-style: italic">euroOptic</span></span> page shows the Right Side of the PMII 5-25x56 L/P P4 Fine MOA Reticle DT 1/4 MOA CCW scope, but if you click-on the Main Photo a new window will open-up that shows the two photos I posted below (Left Side Rear and Right Side Profile). <span style="font-weight: bold"><span style="font-style: italic">Direct link to photos:</span></span>

<span style="font-size: 11pt"><span style="font-weight: bold">Look closely at the photos and/or use your browser's <span style="font-style: italic">"Zoom"</span> tool. <span style="font-style: italic">Notice that the Elevation Turret reads to "65" MOA.</span></span></span>
PMII5-25X25MOALSRA798x462.jpg

PMII5-25X25MOALS-798x418.jpg



Keith
 
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