Mildot scopes question

MarcinG

Hi.

I had some problems with holdovers on my rifles ( i have brno2e 22lr with 3-7x mildot hawke and 455 17hmr with 5.5-16x mildot hawke ). I made assumption that @full mag mildot = 1/1000 of distance to target (10cm @ 100m etc). But curiosity made me download hawke xact app to discover that above is true only for x10 mag for all rectiles... what a stupid idea. On 1 scope it is never true as it is x7 max and on other it is only true at half mag... not too mention hawkes 17hmr scope (which i planned to buy) with all pois marked and holding true for x10 only (scope is max 12 or 14x...).


Are there any other manufacturers making scopes in what in my mind appears as a more logic way of marking mildots @ full mag? So you can use full power of the scope and being able to asses distance to known size target or size of target at known distance? And not too expensive please.

extremetaz

Well the obvious solution is to just opt for an FFP (first focal plane) scope that suits your budget and then your reticle will always be true regardless of what mag you're at. While you're at it you could also look into scope with a mil-mil setup rather than the standard mil-moa system.

Staying in the realm of SFP I'm not aware that 10x rule is cardinal, in fact I'm pretty sure it various from scope to scope in most cases - you'll usually note a differently coloured digit on your zoom collar, as far as I'm aware, that setting marks your true reticle magnification.

Knowing your preferred mag and just multiplying your reticle view by the ratio of 'mag:true mag' will also do the job though, so in the case of 7x for 10x true, your 10cm becomes 7cm at 100m and so on.

*edit: apologies, I have that calculation the wrong way around. Should be that 10cm becomes 14cm (as the field of view increases [ie: you zoom out from 'True'] the distance represented between the dots increases, what I had originally had that relationship inverted. 10cm would become 7cm at 14x assuming true @10x)

MarcinG

extremetaz wrote: »

Well the obvious solution is to just opt for an FFP (first focal plane) scope that suits your budget and then your reticle will always be true regardless of what mag you're at.

me before checking x-act

I thought that no matter what FP scope there is only 1 "true" setting (unless of course scope has single mag).

What is my understanding of "true": predictable and easy to calculate ratio between space between mildots and distance to target.
I understood this was the idea behind mildots: say 20 cm known target appears on scope as 1mildot wide = you are 200m from target so you can pick holdover calculated in 10cm/mildot units. I think FFP or SFP is irrelevant as long as above is true at max magnification (ps what is the point of caliber specific reticle with zoom 3-16x when PoI are only true for x10?, not to mention scope which has less than x10 therefore is NEVER true mildot despite name...)

Ps am I right that in FFP scope crosshair is getting thicker (in respect to you target) with progressing magnification?

Staying in the realm of SFP I'm not aware that 10x rule is cardinal, in fact I'm pretty sure it various from scope to scope in most cases - you'll usually note a differently coloured digit on your zoom collar, as far as I'm aware, that setting marks your true reticle magnification.

This is very good hint to look for. Non of my scopes is marked unfortunately.

Knowing your preferred mag and just multiplying your reticle view by the ratio of 'mag:true mag' will also do the job though, so in the case of 7x for 10x true, your 10cm becomes 7cm at 100m and so on.

Below is a product of me playing with x-act app for quite some time and trying to replicate similar POI calculating it by hand:

i wish it would be that easy. because i think you need to take to account trajectory of bullet progressively changing its path. even @ 10x it (at least in x-act app) is slightly off but when you use 16x it get nearly exponentially off and you can simply forget about 1.6 etc. especially that i'm working backward compared to program - i'm finding holdovers for set distances while program finds poi for set holdovers. Is this something you ever tried to calculate and test in real life? i have no access to range (and to actually check it you will need at least 200m distance)

That make me think that using turrets is the only way to go and whole mil dot is not quite as good as i thought it is? anyone to verify ? is there much sense in trying to use turets on cheap hawke scope?

clivej

The spacing between the dots is
100mm @100m

So put out 2 marks, ie dots, 100mm apart at 100m. Zoom in or out until the scopes mil dots are on the target dots and you will have the correct zoom value for your scope.

MarcinG

Thank you guys.

1st i noticed that im tired
2nd that hawke x act is not measuring anything in m. It is converting round yds to m.(so it zeros at 91m rather than at 100 etc).
3rd drop data is again slightly different to what i used.
4th as i mentioned in first post app is calculating backwards to me. When i picked a half moa recitle it is easier to see that calculated by my and app values are not far of
5th just noticed that xact has a bug. I have 2 screenshots with same settings and different readings. Like x16 mag reading intercepts for x10 which confused me even further as i used screenshots downloaded to pc as my mobile kept on locking screen on me.

So again it looks like @10×; hawke scope is reading ok.
But question remain is there any other scope with max zoom mildot?

Cass

extremetaz wrote: »

Staying in the realm of SFP I'm not aware that 10x rule is cardinal, in fact I'm pretty sure it various from scope to scope in most cases ...........

Yup

Some scope manufacturers use 12 power, some 18 power, some use 22 power, and others will say its true at max mag where the mag is below a given value.

extremetaz

Whilst I surmise that you may have spotted some of this by now in any case, I'm gonna go ahead and throw the info out there anyway.

MarcinG wrote: »

I thought that no matter what FP scope there is only 1 "true" setting (unless of course scope has single mag).

Nope, the big advantage of FFP is that the reticle is ALWAYS true on account of the fact that it changes with your zoom level so the relationship between the field of view and the reticle remains constant.

MarcinG wrote: »

What is my understanding of "true": predictable and easy to calculate ratio between space between mildots and distance to target.

Nope, I'm afraid not.

'True' only means that the fixed reticle size (SFP) is accurately indicating the value between the various marks on the reticle with respect to your field of view (FoV). Hence, if your scope is 'True' at 12x, then only at 12x can you apply the reticle marks directly to PoI shift in your field of view. At 6x, that 1 mildot spacing is actually 2 milliradian - hence my remark above about the ratio of mag:true being applicable as a scalar to any calculations you make on an SFP scope. Beyond that scalar, the calculation is entirely unchanged.

MarcinG wrote: »

I understood this was the idea behind mildots: say 20 cm known target appears on scope as 1mildot wide = you are 200m from target so you can pick holdover calculated in 10cm/mildot units.

...and that is correct IF your reticle is 'True'. Which will always be the case in an FFP scope, and will be the case at a specific mag on an SFP scope.

MarcinG wrote: »

I think FFP or SFP is irrelevant as long as above is true at max magnification

It will always be true for the FFP, but will only be true for the SFP at its calibrated magnification setting.

MarcinG wrote: »

(ps what is the point of caliber specific reticle with zoom 3-16x when PoI are only true for x10?, not to mention scope which has less than x10 therefore is NEVER true mildot despite name...)

again that 10x thing isn't a universal standard, however the point you raise is fair - that though, is a WHOLE other discussion.

MarcinG wrote: »

Ps am I right that in FFP scope crosshair is getting thicker (in respect to you target) with progressing magnification?

Yes

MarcinG wrote: »

i wish it would be that easy. because i think you need to take to account trajectory of bullet progressively changing its path.

Nope - shift your PoA, shift your PoI, it's that simple - mag has nothing to do with that. The only thing mag affects is how your perceive your PoA shift (ie: 1mildot is only actually 1milliradian at x-mag, else scale by ratio of mag:x as mentioned before)

MarcinG wrote: »

That make me think that using turrets is the only way to go and whole mil dot is not quite as good as i thought it is? anyone to verify ? is there much sense in trying to use turets on cheap hawke scope?

Not the only way to go at all - like everything else they each have their place, and there's no small amount of personal preference involved as well.

IME dialling will give you more precision, which is nice on the range. In the field though, the certainty of knowing how your scope is set and not having to think about what the last adjustment you made was means more than that superfine precision - as I said though, that's just me, and I presently only use 22LR in the field; the lads that reach out that bit farther may well think differently.

Vegeta

extremetaz wrote: »

IME dialling will give you more precision

Just as an addition to this, modern reticles are generally more precise than modern scope turrets. Whether or not a person is more accurate/precise dialling and using the reticle centre versus holding over with reticle hash marks is certainly a point worth discussing.

Here's an example of errors while dialling. I guess it doesn't really matter if you collect/validate your own drop data as this error will be accounted for but maybe if just using a ballistic calculator it will not have this error accounted for.

https://www.youtube.com/watch?v=xaT8ApNt8MY

tac foley

Cass wrote: »

Yup

Some scope manufacturers use 12 power, some 18 power, some use 22 power, and others will say its true at max mag where the mag is below a given value.

All three of my Nightforce NSX-series have a hashmark R at x22 magnification.

Can't say for any of the others as they are all standard, duplex or #4 reticles.

tac

MarcinG

extremetaz wrote: »

Whilst I surmise that you may have spotted some of this by now in any case, I'm gonna go ahead and throw the info out there anyway.

Thank you.

Nope, the big advantage of FFP is that the reticle is ALWAYS true on account of the fact that it changes with your zoom level so the relationship between the field of view and the reticle remains constant.

Not quite sure what i was thinking before of haw FFp scope works

Beyond that scalar, the calculation is entirely unchanged.

Yes as i stated in previous posts i think i found why it not worked for me.

MarcinG

Vegeta wrote: »

Just as an addition to this, modern reticles are generally more precise than modern scope turrets. Whether or not a person is more accurate/precise dialling and using the reticle centre versus holding over with reticle hash marks is certainly a point worth discussing.

Here's an example of errors while dialling. I guess it doesn't really matter if you collect/validate your own drop data as this error will be accounted for but maybe if just using a ballistic calculator it will not have this error accounted for.

This is quite bad for price tag on that scope...
I never tried to use turrets on my hawkes as i was afraid that it won't even go back to proper zero (and taking price difference i may not be far from truth...). Not that i shoot flies at 100m but if something has a potential to make things worst i'm avoiding it usually.

MarcinG

I emailed hawke and they sent me a little pdf file. When printed at 100% (for help it has some metric patterns on it to measure if scale is correct) it suppose to be spot on with mildots at 25 yds at right mag. I tested my bigger scope(at25yds Used hawke rangefinder for distance estimate) to find right mag (smaller scope at 7x is never mildot despite name) and it looks like right mag for hawke airmax 5.5-16x44 AO is more like x8.7 than 10.so generally speaking whole idea of calculating anything is worthless (possibly on the cheap scopes only but i'm yet to buy expensive one) as app calculated POI will also be wrong as they calculated with idea that scope is true at x10 but it isn't. Better idea will be so spend some time at the range/farm and check by experience what POI you get for each mildot and keep record of it handy. This is from a perspective of someone who had a hope to be able to estimate distance to a small target and bdc using simple maths.