Tatical scope question..

Discussion in 'Deer Hunting' started by BLKCLOUD, Oct 24, 2007.

  1. BLKCLOUD

    BLKCLOUD Member

    Messages:
    378
    State:
    Pulaski Tn
  2. GMC FishHauler

    GMC FishHauler New Member

    Messages:
    1,335
    State:
    Waco, Texas, Un
    that is 1" at 100yrds is around one MOA. 4" at 400yrds is one MOA.
    28" at 400 yrds is 7 MOA. If you have 1/4 MOA adjustments on your scope for your elevation then you need to go up 28 clicks.
     

  3. BLKCLOUD

    BLKCLOUD Member

    Messages:
    378
    State:
    Pulaski Tn
    The way I figured it was..1" = 4 clicks @ 100 yards if it dropped 28 inches then I would need to have it shoot 28 inches high at 100 yards which was 28X4 112 clicks..I knew that wasnt right..I have never done any scope adjusting while shooting just always held over the target..thanks!!
     
  4. GMC FishHauler

    GMC FishHauler New Member

    Messages:
    1,335
    State:
    Waco, Texas, Un
    another option for those long range shots would be to zero your gun at 300 yrds and see where your zero is at 100. It will prob be about 3.5" high (not for sure) but the drop should be pretty dramatic after 300. Making your gun shoot 8-10" low at 400. Like i said, i am not positive about this cal or your gun, barrel length comes into play alot.
     
  5. chambers bd

    chambers bd New Member

    Messages:
    1,134
    State:
    Sautee,Geo
    The scope on your ebay site is a 1/8 moa{the pictured one}

    [FONT=Arial,Helvetica,sans-serif]The Mil-Dot reticle[/FONT]
    [​IMG]
    [FONT=Arial,Helvetica,sans-serif] [​IMG][/FONT]
    [FONT=Arial,Helvetica,sans-serif]This reticle was developed in the late 1970s to help U.S. Marine snipers estimate distances, and is now standard for all military branches. The space between dot centers subtends one milliradian(mil) hence the name mil-dot. Contrary to popular belief it does not stand for "military dot". One mil. subtends 3.6 inches at 100 yards or 36 inches at 1,000 yards. To use this system effectively you must know the size of the target. For instance most people are an average of 6 feet tall or 2 yards. The formula used for determining range to the target is (size of target x 1000 divided by number of mils the target covers).[/FONT]

    [FONT=Arial,Helvetica,sans-serif][​IMG][/FONT]
    [FONT=Arial,Helvetica,sans-serif]Height of target (yards) X 1,000 = Range (yards)[/FONT]
    [FONT=Arial,Helvetica,sans-serif]Height of target (mils)[/FONT]​


    [FONT=Arial,Helvetica,sans-serif]You can do these calculations with a calculator or use a reference table like the ones listed below. But remember that your answer is only as accurate as the numbers you plug into the formula. An error of just a 1/4 mil will cause an error in target range. Also an error in estimating the size of your target will cause an error in target range.[/FONT]


    [FONT=Arial,Helvetica,sans-serif]The top line on the table represents the size of the target as measured in feet or inches. The second line represents the conversion of the foot measurements to yards. The left column shows the mil measurements to the nearest 1/2mil. The mil scale can be split to the nearest 1/8mil. for a more accurate range measurement. To use the table follow the instructions below.[/FONT]


    [FONT=Arial,Helvetica,sans-serif]1. Estimate height of target and locate across the top.[/FONT]
    [FONT=Arial,Helvetica,sans-serif]2. Measure height of target in mils and locate down the side.[/FONT]
    [FONT=Arial,Helvetica,sans-serif]3. Move down from the top and right from the side to find the range in yards.[/FONT]
    [FONT=Arial,Helvetica,sans-serif][​IMG] [​IMG][/FONT]
    [FONT=Arial,Helvetica,sans-serif]Range Estimating with the Mil-Dot Reticle[/FONT]
    [FONT=Arial,Helvetica,sans-serif]Dots are spaced in one mil (milliradian) increments on the crosshair. Using the mil formula, a table can be created like the ones above that is based on the size of the object being targeted. Just look through the scope, bracket the object between dots, and refer to the table for an estimated distance to target. [/FONT]
    [FONT=Arial,Helvetica,sans-serif]The radian is a unit less measure which is equivalent, in use, to degrees. It tells you how far around a circle you have gone. 2 PI radians = 360 degrees. Using 3.14 as the value of PI, 6.28 radians take you all the way around a circle. Using a Cartesian coordinate system, you can use "x"- and "y"-values to define any point on the plane. Radians are used in a coordinate system called "polar coordinates." A point on the plane is defined, in the polar coordinate system, using the radian and the radius. The radian defines the amount of rotation and the radius gives the distance from the origin (in a negative or positive direction). [/FONT]
    [FONT=Arial,Helvetica,sans-serif]The radian is another measurement of rotation (the degree/minute/second-system being the first). This is the system used in the mil-dot reticle. We use the same equation that we used before, but, instead of your calculator being in "degree" mode, switch it to "radian" mode. One milliradian = 1/1000 (.001) radians. So, type .001 into your calculator and hit the "tangent" button. Then multiply this by "distance to the target." Finally, multiply this by 36 to get inches subtended at the given distance. With the calculator in "radian" mode, type:[/FONT]

    [FONT=Arial,Helvetica,sans-serif]tangent(.001)*100*36 = 3.6000012"[/FONT]​


    [FONT=Arial,Helvetica,sans-serif]So, one milliradian is just over 3.6 inches at 100 yards. If we extrapolate, two milliradians equal about 6 feet at one-thousand yards. The mil-dot reticle was designed around the measurement unit of the milliradian. The dots, themselves, were designed with this in mind and the spacing of the dots was also based upon the milliradian. This allows the shooter to calculate the distance to an object of known height or width. Height of the target in yards divided by the height of the target in milliradians multiplied by 1000 equals the distance to the target in yards. For example, take a 6-foot-tall man (2 yards). Let's say that the top of his head lines up with one dot and his feet line up four dots down. So: (2/4)*1000 = 500 yards away. This same technique can be used to estimate lead on a moving target or to compensate for deflection on a windy day. The distance from the center of one dot to the center of the next dot is 1 milliradian. We are told (by Leupold) that the length of a dot on one of their reticles is 1/4 milliradian or 3/4 MOA (Given this much information, one can determine that the distance between dots is 3/4 milliradian.).* I use the term "length" because the mil-dot is not round in all cases. It is oblong in some scopes and round in others (tasco). The width of each dot is an arbitrary distance and is not used for any practical purpose. Like a duplex reticle, the mil-dot reticle is thicker towards the edges and uses thin lines in the middle where the dots are located and the crosshairs cross. The distance between the opposite thick portions is 10 milliradians on Leupold scopes. [/FONT]
    [FONT=Arial,Helvetica,sans-serif]*NOTE: 1/4 milliradian = .9" and 3/4 MOA = .785", so, obviously, a mil-dot cannot be both 1/4 milliradian and 3/4 MOA. The maker of the mil-dot reticles for Leupold explains: the dots on their mil-dot reticles are 1/4 mil. They are not 3/4 MOA. Apparently, Leupold just figured that more shooters understand MOA than milliradians, so they just gave a figure (in MOA) that was close, but not super precise. [/FONT]
    [FONT=Arial,Helvetica,sans-serif]To use a mil-dot reticle effectively, all one need remember is that the distance between dot centers is 36" at 1000 yards. This lets you determine the range of a target of known size. At that point, you can dial the scope in for proper elevation OR use the dots to hold over the proper amount. The dots on the horizontal crosshair can be used to lead a target (if you know the range to the target, then you'll know the distance between dots, and thus the distance to lead) or to compensate for deflection.[/FONT]


    [FONT=Arial,Helvetica,sans-serif]Minute-Of-Angle[/FONT]
    [FONT=Arial,Helvetica,sans-serif]The term "minute-of-angle" (MOA) is used regularly by target shooters at the range, but is probably understood, thoroughly, by few (the same goes for mil-dots). Defined loosely, one MOA = 1" @ 100 yards; so, if you shot your rifle 5 times into a 100-yard target and every shot went into a one-inch circle you had drawn on the paper, then your rifle could be said to shoot 1 MOA. Likewise, if every shot goes into a two-inch circle at 200 yards, then you're shooting 1 MOA. A 10-inch group at 500 yards would be 2 MOA. [/FONT]
    [FONT=Arial,Helvetica,sans-serif]Now for the fun part. There are 360 degrees in a circle. Each degree can be broken down further into minutes. There are 60 minutes in a degree. Likewise, there are 60 seconds in a minute. Now, to figure out the distance subtended by 1 minute at any particular distance, we need merely to plug those two values into a simple trigonometric equation. The tangent function fits the bill nicely. Here's the equation:[/FONT]
    [FONT=Arial,Helvetica,sans-serif]tan(angle) = distance subtended/distance to the target (units must be consistent--e.g., 1/36 of a yard [1"] divided by 100 yards)[/FONT]
    [FONT=Arial,Helvetica,sans-serif]Now, we know the angle (1 minute or 1/60 of a degree) and we know the distance to the target (100 yards), but we need to figure out the actual distance subtended at the target (i.e., is 1 MOA actually 1" @ 100 yards?). What we need to do is solve for "distance subtended." Here's our final equation:[/FONT]

    [FONT=Arial,Helvetica,sans-serif]tan(angle)*distance to the target = distance subtended[/FONT]​


    [FONT=Arial,Helvetica,sans-serif]Make sure your calculator is in "degree" mode (as opposed to "radian" or "gradian") and type in 1/60 (for degrees) and hit the "tangent" button. Then multiply that by 100 yards. This should give you the distance (in yards) subtended at 100 yards. Multiply this by 36 to get inches. The answer should be:[/FONT]

    [FONT=Arial,Helvetica,sans-serif]1.047197580733"[/FONT]​


    [FONT=Arial,Helvetica,sans-serif]This is just a hair over the commonly quoted "one inch." At 1000 yards, this would be almost 10 1/2 inches. Apparently, it is just a coincidence that 1 MOA happens to be REALLY close to 1" @ 100 yards. It is, however, quite convenient.[/FONT]
     
  6. ShilohRed

    ShilohRed New Member

    Messages:
    4,339
    State:
    West Tn
    I would also have it set up at 300 yards. That way you can hold a little low and still hit and at 400 yards hold a little high until you see where its hitting. And then you can see where it needs to be.
    Pete
     
  7. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Getting it sighted is a small problem.
    Your problem is going to be that scope holding a sight in through the power range.
    Second problem is going to be trying to get a sight picture through the scope with that much of a power range. One minute you are going to be all up on top of the scope and the next minute you'll be hanging on the tail end.
    Third is going to be clarity.

    I have a 6-24x44. I dont use it over 16 power much for all of the above reasons. Mine is a Tasco competition sillouette scope.
    I do like high turret adjustments. You can dial it right in with your fingers.
     
  8. GMC FishHauler

    GMC FishHauler New Member

    Messages:
    1,335
    State:
    Waco, Texas, Un
    i would go with something in the likes of a Leopold M3A.
    This is a military sniper scope. The elevation is adjusted 1moa and the windage at 1/2 moa. This is as fine tuned as i have ever found a scope to need to be.
    When i was in the army, we used this scope and .308 rifle. we could make 1 shot hits to over 800 if had a steady or consistant wind. we could make head shots out to 400 easily. In the bat. sniper contest my team one, the winning shot was an 1100yrd shot and we got that in 2 shots. The second place team got it in 3.
    One thing i can recommend for distance shooting with any round is to spend alot of time on the range. THis and keeping a log of every enviromental factor and having a good spotter can get almost anybody hitting ridiculously long shots.
     
  9. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    I wasnt too clear in that last post.
    What I should have said is, those high power Tasco scopes suck.
    I own one and still use one even though it sucks. The only reason I do is because I have it thumping so darn good out to 400 yards that I hate to have to get a new scope to that point.
    They are junk. You'll never be able to utilize its full range of powers and get what you are going to expect from it.

    Will it work? Yes, mine does, but I'm only using half of the scope to do it.
    Something like a 4-16 power in Leupold, Nikon etc, you would much more pleased with.
    It holds up very well and holds a sight in. I can leave a sight in and come back to it and it still on. Its still a junk scope on the higher power settings.
    When I do replace it I'll more then likely go with a max of 16 power.

    There is just too much of a change in eye relief on those high power scopes and having to climb all up on it or back away away from it isnt going to help your shooting. Its going to make it darn near impossible to develope the "pocket" in which you get accustomed to laying and staying in when on the firing line.
    When you throw that rifle up you want a sight picture. You dont want to have to find the sight picture.
     
  10. Kutter

    Kutter New Member

    Messages:
    5,379
    State:
    Arnold, MO
    As I got older, it was harder for me to judge distances. Where I hunt, 200-250 yard shots are common and alway possible a bit further. After doing a lot of research, I ended up using a Browning A-Bolt in 7mm Rem mag with a Leupold Vari-X III 4.5-14 x 40. I zeroed it in at 200 yards. Now, If it's 50 yard or 400 yards, I still know I can aim dead center on the heart and know that deers going down. I can't remember the details of drop/rise at various distances, but I do know it will stay in the killing circle and do the damage needed once it gets there. As you can see, I no squat about all the fancy trajectories an such. I knew at the time I was researching, but theres a lot I used to know that I can't bring back anymore. That was one reason for making the decision I made regarding rifle and scope. I got it right, now I don't have to remember why or how. LOL
     
  11. BLKCLOUD

    BLKCLOUD Member

    Messages:
    378
    State:
    Pulaski Tn
    It looks to me if you zeroed the 7mag at 200 then a 400 yard shot would be a 20 inch drop.. you may be having trouble judging distances if it hits dead on at 400 yards..:smile2::smile2:
    7mm Rem Mag 150 BTsb Nos 3130 3221
    200yard zero-2.6
    300 yards -9.9
    400 yards-22.6
     
  12. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Dont take anything off a drop table as gospel.
    There are too many variables from rifle to rifle, load to load to say at 300 yards its going to drop this amount.

    I have a .308 with a 26" inch barrel. I can tear that page out of the book, ball it up, and throw it away and never miss it.
    Its nowhere even close.

    You'll never know your drop until you shoot and figure it out.
     
  13. Kutter

    Kutter New Member

    Messages:
    5,379
    State:
    Arnold, MO
    Keith, your looking at the 100 yard sight in.
    Maybe I should stick with 300 yards, LOL
    Sighted in at 200 yards, it stays within 6.4 inches according to the chart. But as Mark said, those charts are just a close guess. No rifle shoots the same as another with the same load. No two loads are always the same. There are too many variables for me to try to comprehend, so I don't even try. Deer never pay attention when you ask them to stand broadside at a perfectly level position, at exactly such an such a yardage. Thats the real reason we shoot them, we hate they won't listen an do as we say.
     
  14. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Ever seen a .308 shoot flatter then .270 while using heavier bullets?
    I have on a measured 400 yard target. Same bullet manufacturer. Same bullet style.
    one rifle is untouched out the box. The other rifle is alot touched from trigger to head spacing, to muzzle crown.
     
  15. Mark R.

    Mark R. New Member

    Messages:
    186
    State:
    Rush Springs, OK
    I used to shoot a 6MM a lot as I lived in a prairie dog patch.
    I had it set at about 1.7' high at 100 yards, dead on at 200.
    Shot the barrel out on that one---------

    My big game rifle (7x64) is sighted dead on at 300 yards that makes it 5-6 inches high at 100 and 200 yards and hold on the top of their back at 400, good for deer or elk hunting.
    Hard to shoot small game up close but I really like it on larger animals.
     
  16. Mark R.

    Mark R. New Member

    Messages:
    186
    State:
    Rush Springs, OK
    After reading the article Brian posted I am going to adjust my 6MM Remington autoloader up from the dead on at 200
    where it is now to 2.3" at 200 and see how I like it.
     
  17. Grits

    Grits New Member

    Messages:
    119
    State:
    Arknasas
    Keith

    As said above, one minute of angle is about one inch at 100, two inches at 200, three inches at 300, etc. There should be something on the top of your scope adjustment know that will tell you. It will say something like "1 click= 1/4'".

    Regardless how your scope works, you need to shoot the rifle at different ranges to see actually where it really shoots. Even if you have all the data, ballistic coefficient of the bullet, barometric pressure, temperature, muzzle velocity, etc., you need to shoot it at different ranges.

    Several if my buddies and I use to go to Wyoming and shot prairie dogs every summer. Our rifles were very accurate and all of us shot a lot; however, we shot the varmints about seven thousand feet. All of us live around sea level. At long range, every-one's rifles always shot high. We would have to zero everything again when we got out there. There is no substitute for practice and familiarity with your rifle. Something else interesting I have noticed, most people have a tendency to shoot over targets at long range. Folks have a hard time believing just how far a lot of rifles shoot and how flat they are.

    Put them in the "X" ring.

    Grits