Range Estimation for veriable power mil dot scope

tgipe · Rookie Member Joined: Jan 06, 2011 Posts: 2

I'm shooting a rem 770 with a Barska 6-24x50 mil dot scope and know the formulas for range estimation with fixed power ie: Height of Target (meters) x 1000 = Distance (meters) mils
but how do I range a dear at verios power settings. The target takes up less mil dots @ 6x as opposed to 10x or 24x respectively. is there a formula for this?
any takers

AS this post is old I have found the fallowing:
My scope is calibrated @ 10X thus if I am on 6X I use the above Formula then multiply by .6/ if 8X .8/ if 14X 1.4 / if 20X 2/if 24X 2.4

Thanks to all I ended up talking to one of my unit's snipers for the assist who mirrored this forrums answer. the Range finder is a good sugestion. I also got dope sheets for verious ranges Razz

gelandangan

Usually a mildot scope is calibrated to a particular magnification power.
Mine for instance is calibrated to 10X.

I am not sure on your Barska scope but I am sure it is either published on the Berska website or it is written in the instruction sheet.

chambered221

To my knowledge 10X is the standard !!!
There should be markings on the power dial for any calibrated power settings.
I know that you can use 20X by cutting your value in half so I would think you could calculate it for any power. Just keep in mind that scopes are not always labeled with actual power.
For example a Leupold VXII 3-9 is actually 3.3-8.6........at long ranges that could be an issue.

slimjim

I tried practicing with my mil-dot reticle at known ranges with know sized targets. Even at 100 yard increments, I wasn't consistent enough in the estimations at the longer ranges where it mattered. Got a laser range finder instead. They fit in your hand now days and are very reliable.

Grumulkin

First of all, 10X isn't necessarily "standard." The scope documentation should tell you what the power setting should be for ranging. Secondly, though not likely in your case, if the scope is a first focal plane scope, you can use it to range on any power.

slimjim

Below is a write-up for using mil-dots to range on deer.

www.eabco.com/Reports/...tRep01.htm

Even though I stopped trying to estimate accurate range to a deer with a mil-dot reticle, I have used a mil-dot or duplex reticle as a quick estimation for in-range, e.g., put the crosshairs on the chest and shoot. To find this in-range or closer, I place an 18" high sheet of paper at my max range without hold over. As an example, with a .270 zero'd at 250 yards with a Leupold 3.5-10X on 10X, if the deer's chest fills or is larger than the distance from the tip of the bottom duplex to the top, the deer is in range (300 yards or closer). If the deer's chest is smaller, I need to take a laser range. This technique can be used with a mil-dot also with the magnificantion you expect to hunt with as a default seting.

RePete

The scope reticle is on the second focal plane and as you adjust the magnification the reticle grows and shrinks, therefore the ranging is done at 10x or what the manufacturer determines. Read the manual.

If the reticle is on the first focal plane, like my S&B, then you can range at any magnification.

stovepipe

if the reticle is on the second plane youll need to find the calibration power if it is not marked on the scope. set a target @ 100y, zero it, then fire for effect @ different powers till you get the propper come up for one dot and mark the power and paralax setings w/ a dot of white nail polish. then you can double or half your ranging based on same if the powers are correct as labled on the ring.

slimjim

Not sure you have to shoot any rounds, stovy. Just set-up a target with markings equivalent to MOA at that range and dial-in the power until they match. E.g., 18 inches = 5 mils at 100 yards.

stovepipe

i never thought of that Embarassed

, good thinkin! i like to send rounds to confirm my settings. gives me an excuse to hear ol' El Kabong speak. Very Happy

slimjim

watch that shoulder!

stovepipe

copy. i def aint anywhere near any loaded firearms right now or for the forseeable future. too much pain and drugs. i ought to know better than to be spouting technical stuff in this condition..... Mad

glockman55

Good info guys...I still agree on the Range Finder too.. Handy tool to have along.

eaglesnester

Unless your scope is first focal plane, you would probably do your milling with the scope set at full power. FIrst focal plane scopes are very exspensive, I dont like em because the cross hairs get bigger as you turn up the power. It works like this. In variable-magnification optics, the magnification setting for the use of the Mil Dot or TMR reticle is determined by whether the reticle is in the first or second focal plane. The easiest way to determine if the reticle is in the first focal plane is to view the reticle through the scope while changing the magnification setting. If the size of the reticle appears to change as the magnification setting is changed, the reticle is in the first focal plane, No specific magnification setting is required to obtain the proper subtension to yield accurate range estimating results. If your reticle does not change with increase in magnification then your reticle is in second focal plane and you would likely do your milling at full power setting. I have two Leupold MK-IV tactical TMR 6.5X20-50MM scopes that are in second focal plane and I love them. One is on my 338/378 and the other is on my 300 Weaterby mag. I use the Near mounting systems on both rifles and they will shoot the wings off a fly at 100 meters.

slimjim

Many high magnification variable-power scopes have their "mil-setting" below maximum magnification. My 2.5 to 16 power Bushnell is set at 10x. A fixed 10x was the standard for snipers for many years. An advantage of not having the mil-setting at high powers is to avoid the affects of heat shimmer during hot conditions. A second advantage occurs when you use your mil-dot for ballistic drop compensation and you have a flat shooting rifle. You can adjust magnification above the mil-setting to tune to the flatter trajectory. My .270 with 130gr GMX and scope set on 11.5x gives me 100 yd zero, 300 yards at the first mil-dot, 400 at the second dot, 500 yards at the 3th, and 600 yards POI at the 4th mil-dot.