doric_prince
Well-Known Member
This rings true ( no pun intended) about what I was told by seller- what scope are you using? Thanks
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stop go decision needed; 20 Moa based good or bad for hunting.
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FISH BOY
Well-Known Member
3x12x56 and a 6x24x56.
doric_prince
Well-Known Member
did you have to use most of their elevation adjustment? Do you know roughly what they are?
scrumbag
Well-Known Member
That's a very small elevation travel for that scope isn't it? I'd have expected better from S&B
I shoot a 7x64 26" barrelled rifle with a 20MOA rail and which I have shot from 100 to 1,200 yds but the scope has a lot more elevation travel.
Given the costs, I'd phone your dealer first thing and explain the situation then see if you can't get some store credit for driving down to get the problem fixed to offset your fuel costs.
I think this is a salutory lesson though, you can't rely on rifles or (particularly UK) dealers getting what you need to you and / or it going together in a short space of time. It pays to build into your planning allowance for someone else's f*ck up
I shoot a 7x64 26" barrelled rifle with a 20MOA rail and which I have shot from 100 to 1,200 yds but the scope has a lot more elevation travel.
Given the costs, I'd phone your dealer first thing and explain the situation then see if you can't get some store credit for driving down to get the problem fixed to offset your fuel costs.
I think this is a salutory lesson though, you can't rely on rifles or (particularly UK) dealers getting what you need to you and / or it going together in a short space of time. It pays to build into your planning allowance for someone else's f*ck up
doric_prince
Well-Known Member
Yes it appears with the bdc elevation is low range, conversely on the model without it it appears to have a greater range of elevation.
on the planning front, yes completely agree with you.
Normally I do just that as this isn’t the first time I’ve experienced a balls up, which wasn’t my fault, however as previously mentioned other dependencies led me through this decision matrix path which impacted timing.
i usually program plan The crap out of, and Analyse to the hilt, decisions /options / costs / compatibility et cetera to the point where my GF calls me obsessed (admittedly I am on the spectrum, so it’s in my nature to do thus). Believe me this is firmly out with my comfort zone in taking such decisions at pace and being thrown by last-minute issues/having to consider taking risks et cetera.
I wonder if the BDC limits the turret dialling range when set. Much like the Zeiss V8 turret only allowing one rotation. Prior to setting the full range of adjustment is available.
I've been worrying about my use of that Sierra data for their "Custom .284 7mm Mag Ammo #4550 at 3000 Feet per Second"
So I've had a go at putting the bullet data into ShootersCalculator.com | Ballistic Trajectory Calculator as a double check.
Bullet data from https://www.sierrabullets.com/wp-content/uploads/2019/10/BC-chart-rifle.pdf
The Polar 4-16x56 has objective bell of 62mm dia. So at a wild guess, that might be sitting say 4mm above e.g. a 19mm Blaser semi-weight barrel. Giving a sight height of 44.5mm or 1.75"
So, putting in BC of 0.436, MV 3000 FPS, scope height 1.75", 200 yard zero, Shooterscalculator predicts:
Which is similar, actually rather flatter shooting, due to the larger sight height effect.
Here's a link to what I did, if you want to play with the numbers: ShootersCalculator.com | Ballistic Trajectory Calculator
If you want the "pure" trajectory of the bullet, try setting sight height =0", zero range =0yards
Then you get the following, from which you can see that using a 20 MOA mount would bring the scope into the centre of its range of adjustment at about 725 yards: Great if you are a long range target shooter, not so much for deerstalking distances.
So I've had a go at putting the bullet data into ShootersCalculator.com | Ballistic Trajectory Calculator as a double check.
Bullet data from https://www.sierrabullets.com/wp-content/uploads/2019/10/BC-chart-rifle.pdf
The Polar 4-16x56 has objective bell of 62mm dia. So at a wild guess, that might be sitting say 4mm above e.g. a 19mm Blaser semi-weight barrel. Giving a sight height of 44.5mm or 1.75"
So, putting in BC of 0.436, MV 3000 FPS, scope height 1.75", 200 yard zero, Shooterscalculator predicts:
Which is similar, actually rather flatter shooting, due to the larger sight height effect.
Here's a link to what I did, if you want to play with the numbers: ShootersCalculator.com | Ballistic Trajectory Calculator
If you want the "pure" trajectory of the bullet, try setting sight height =0", zero range =0yards
Then you get the following, from which you can see that using a 20 MOA mount would bring the scope into the centre of its range of adjustment at about 725 yards: Great if you are a long range target shooter, not so much for deerstalking distances.
That is correct. The BDC II has a range from zero to 10 MRAD, whichever 'scope it is fitted to. They can be moved around within the total range available when setting the scope up. then locked with the allen screw.
Nevertheless, for this particular 4-16x56 Polar model, even with the Posicon turrets fitted, which allow the entire range, the total adjustment range is only 15 MRAD. I.e +/- 25 MOA. The lower power versions have larger ranges.
But when using the entire adjustment range, there is, as I said earlier, an interaction between windage and elevation, e.g. if the elevation is near the extreme, the usable windage adjustment becomes restricted. This is normal for most 'scopes, its just that the Posicon turrets make this clear, having a green zone indicating normal adjustment range, but a red zone showing when the adjustments are exceeding these limits.
See Jagd for a description of how the various turrets work.
BDC II LT (Elevation)
Lockable (LT) Bullet Drop Compensation (BDC II) elevation turret with Sub-Zero Clicks (SZC)
The BDC II is primarily suited to long-distance shooting or hunting. The turret cap is released with a conventional Allen Key for zeroing and a retaining screw prevents it from getting lost. The turret combines an enhanced adjustment range with an effective BDC II locking function which avoids unintentional adjustment. Marks and numbers are in MRAD. The number “1” is standing for 1 MRAD which is 10 cm/100 m. It is equipped with 2 Sub-Zero Clicks (SZC) and is capable of 10 MRAD.
Posicon CT (Elevation and windage)
Capped (CT) Posicon turret adjustments elevation and windage
The Posicon (Position control) turret adjustments are color-coded and enables you to identify the reticle position within the riflescope at a glance. With the position indicator in the green range, the reticle is inside the ideal adjustment range. This eliminates any possibility of binding the adjustment within the riflescope body and ensures a simple and perfect way of zeroing. The red range serves as a warning: this reserve precludes the use of the full range of adjustment in the opposing adjustment’s direction (e.g. elevation vs. windage travel adjustment). The point of impact is moved by 1 cm/100 m on every click. A too low point of impact (POI) is corrected by rotating the elevation turret clockwise towards the letter H or U (= Up). If the POI is too high the turret has to be turned towards letter T or D (= Down). For windage it is the same procedure except with letters L (= Left) and R (= Right). After the rifle has been sighted in, the silver perimeter ring, with an index mark, can be rotated to serve as a zero indicator. The Posicon turret adjustment is a unique Schmidt & Bender feature and reflects our superb engineering and quality standards.
I think the new politically correct version is “Janet, John and Other”
Anyone got the "Janet and John" version of this?
I have used 20moa rails on all of my rifles as standard, as do mo most of my mates, and thousands of shooters across the globe. I have never ever heard of anyone struggling with such a set up at 100m.
Janet, John and Jx
Depends on the scope and rifle.
I had a 20 Barton Gunworks MOA rail on a Howa and it would not give a 100m zero with a Leica ER.
Put that rail in the bin where it belonged and got a ERA 0 MOA rail, perfect.
Conh, I have had a few 20MOA combinations not working or not working well. Not working well is for example a S&B scope at the edge of adjustment which has less up down travel if one uses more windage travel. Adjustment window is Round 'ish' not a square box. Hence Posicon
Not all 20MOA stamped products are actually 20 MOA. Not all barrels are 100% fitted straight in the receiver. Hunting range of S&B mostly has small available travel.
Even my 45 MOA range Conquest would not adjust to some "20 MOA" rail set up rifles. If one wants realistic MOA values on mounts , go Spuhr, by far the best.
Have no issues with my 3-20 PMII ... it has over 3m travel at 100m.
edi
Not all 20MOA stamped products are actually 20 MOA. Not all barrels are 100% fitted straight in the receiver. Hunting range of S&B mostly has small available travel.
Even my 45 MOA range Conquest would not adjust to some "20 MOA" rail set up rifles. If one wants realistic MOA values on mounts , go Spuhr, by far the best.
Have no issues with my 3-20 PMII ... it has over 3m travel at 100m.
edi
Curious as to why you might think that a 20 MOA rail should be the standard fit ? Have you worked out what benefit (or dis-benefit) it might actually be giving you, as in facts and data.
Unless you are shooting long range targets (at well beyond stalking ranges) they mostly aren't needed, in fact counter-productive.
But hey ho, maybe its just a marketing thing. Slap on a 20MOA rail as part of the kit, claim that it adds value and adds TactiCool credentials, result. Obviously a discriminator in deciding on a purchase. Boring old straight mounts, blurgh. 20 MOA rail included, tick box, that obviously must be an added value, just look at what it might cost to buy one separately.
Then others can spread FUD, what, you aren't using a 20MOA (or whatever) thingummy, well how old fashioned. All the cool kidz know so much better.
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Surely the answer to the OP's question is to get one of these and a 0 MOA rail?
Regards
JCS
JCS
I run a 20 MOA rail on my 7 Mag and have seen no disadvantage to the incline rail at all. Using the figures above, the scope in question has 15 milradian adjustment so 7.5 up and 7.5 down of the centre of adjustment and the BDC turret limits the travel to 10 milradian when set.
Assuming the barrel is true to the mounting interface then with a 0 MOA rail there will only be 7.5 milradian of adjustment available before no further elevation travel is possible as limited by the scope itself. If the 20 MOA rail is used (20MOA = just under 6 milradian) there will be 7.5 +6 = 13.5 milradian elevation available within the scope which means that the BDC can function fully as intended without running out of elevation. Furthermore at the low end of the adjustment range there will still be over 1.5 milradian adjustment possible which should prevent distortion of the adjustment values per click. Personally with this combination I would prefer the 20MOA rail that allows full BDC travel over a 0 MOA rail that does not. I would definitely get the scope mounted and take the big stick up to Scotland to spank a few hinds! Once you have done that you really won’t give a toss how many MOA are on the rail!!
Assuming the barrel is true to the mounting interface then with a 0 MOA rail there will only be 7.5 milradian of adjustment available before no further elevation travel is possible as limited by the scope itself. If the 20 MOA rail is used (20MOA = just under 6 milradian) there will be 7.5 +6 = 13.5 milradian elevation available within the scope which means that the BDC can function fully as intended without running out of elevation. Furthermore at the low end of the adjustment range there will still be over 1.5 milradian adjustment possible which should prevent distortion of the adjustment values per click. Personally with this combination I would prefer the 20MOA rail that allows full BDC travel over a 0 MOA rail that does not. I would definitely get the scope mounted and take the big stick up to Scotland to spank a few hinds! Once you have done that you really won’t give a toss how many MOA are on the rail!!
Frankly, this whole riflescope and mounts thing has become completely backwards.
Back in the day the ultimate was an Unertl.
The 'scope itself was uncompromised, everything aligned perfectly.
Then it was put into mounts that could move it around externally, and even protect it from recoil using a spring.
So, my modest proposal, let the optics people make straightforward telescopes of sublime optical quality, uncompromised by any adjustments, other than objective and ocular focus.
Let the mount people make mounts to take these straight tubed things, wherein the zeroing mechanism is part of the mount. That will provide plenty of product differentiation and opportunity to refine the mechanisms. Put stepper motors in to twiddle them automatically according to input from your electronically integrated targeting solutions, LRFS, Kestrels, whatever. Accelerometer/inclinometer cant correction, no need to hold the rifle straight up and down, and so on.
Al that adds up. Except that why would you possibly think that you need "full BDC travel" even for any conceivable long range use ?
Being a bit cynical, however this rifle ends up being used, it won't need 10 MILs of correction for anything, if dialled it will probably use no more than two, over all stalking distances. But there again, given a reticle with subhashes, maybe use those instead of dialling. But, oh, how might that work if the reticle is in the second focal plane, and I've twiddled the zoom (and by the way at what mag. are those markings correct ?) Well there is a lot to think about with a new 'scope, a new rifle, a new chambering, and whatever, when the priority might be to simply shoot a deer with what you've got.
I haven't previously touched on this, to avoid confusion, but if I have not completely messed up the figures that I have put forward, the flat shooting "7 Mag" could get out to as far as 825 yards with just a 25 MOA 'scope correction from nominal, just possible even with the particular 'scope being discussed.
Back in the day the ultimate was an Unertl.
The 'scope itself was uncompromised, everything aligned perfectly.
Then it was put into mounts that could move it around externally, and even protect it from recoil using a spring.
So, my modest proposal, let the optics people make straightforward telescopes of sublime optical quality, uncompromised by any adjustments, other than objective and ocular focus.
Let the mount people make mounts to take these straight tubed things, wherein the zeroing mechanism is part of the mount. That will provide plenty of product differentiation and opportunity to refine the mechanisms. Put stepper motors in to twiddle them automatically according to input from your electronically integrated targeting solutions, LRFS, Kestrels, whatever. Accelerometer/inclinometer cant correction, no need to hold the rifle straight up and down, and so on.
Al that adds up. Except that why would you possibly think that you need "full BDC travel" even for any conceivable long range use ?
Being a bit cynical, however this rifle ends up being used, it won't need 10 MILs of correction for anything, if dialled it will probably use no more than two, over all stalking distances. But there again, given a reticle with subhashes, maybe use those instead of dialling. But, oh, how might that work if the reticle is in the second focal plane, and I've twiddled the zoom (and by the way at what mag. are those markings correct ?) Well there is a lot to think about with a new 'scope, a new rifle, a new chambering, and whatever, when the priority might be to simply shoot a deer with what you've got.
I haven't previously touched on this, to avoid confusion, but if I have not completely messed up the figures that I have put forward, the flat shooting "7 Mag" could get out to as far as 825 yards with just a 25 MOA 'scope correction from nominal, just possible even with the particular 'scope being discussed.
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Because my rifles are all regularly shot out to their maximum effective ranges? I’m pretty sure the deer don’t realise that I’m using 20moa mounts and I have the added bonus of being able to use all of my scopes available elevation adjustment when shooting long range? You seem very upset by this
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