8 comments on “I want shoot to 1000 yards, how much Internal Adjustment do I need in a riflescope to get there?

  1. First you need to understand what a scope does on MOA adjustments. An MOA means minute of angle.. Not which rifle you have. And that a scope adjusts for a bullet, not distance or a target.
    Just the bullet. A minute of angle is referenced at 100 yds. where it is equal to 1.047 inches ( 1 inch if you wish). When an angle leaves you on a rise, at 100 yards it might be the one inch. When that same angle travels away and upwards, say 5 miles , that same minute might be a thousand inches up. So a one MOA click at that five miles would equal 1000 inches.
    Each 100 yards on a MOA scope will equal another inch. At 100yds.= 1 inch … 200 yds. = 2 inches… 300 yds. equal 3 inches etc.. So each distance needs that distance measure of inches used for calculation.
    You must have the ballistics chart for the box of rounds you have at the moment.. Ballistics vary on sporting rounds.. Accuracy requires repeatable ballistics so match rounds are required. When you buy rounds again they may be from a different batch or “lot” so the ballistics of it must be used instead. A range card must be made and referenced for shots..
    If your round ballistics show it drops 20 inches at 1000 yards, you know a minute of angle MOA equals 10 inches at 1000 yards, so you will adjust the bullet up 2 moa..
    Most rounds drop about 200 inches at that range so you need to adjust 20 MOA for that.
    Just remember you are using the scope to control the round. Not the target or rifle..

    • great comment! grain, barrel spin and shape of the projectile also change dramatically the performance.
      i suggest starting with avail loads commercially and learning the MOA for that partucular weapon system and then playing with the other variables once a consistent grouping occurs. competition shooting is great, but the real adrenalin comes from knowing your weapon system and being able to accomodate real life situations that could occur in the field and being able to switch for a needed L+D situation. that will bring the most confidence in mastering your weapon.

  2. I think a LOT depends on the scope being used. At 50-100 yards you might be able to get away with a cheaper scope, but going these long distances take extreme precision.

    • This is very true. At close ranges and for minimal use, cheap glass is fine. Where they fall apart is when you are using them a lot, say, like at a sniper competition or school where you might be on the scope for hours. Eye strain gets pretty bad with GOOD glass. With mediocre glass you will suffer headaches at some point if you are constantly starting through some of the really bad glass. Resolution and clarity is another area. And this, or the lack of it, in part, are what causes eye strain. The image in cheap glass falls apart at the edges and often just outside the central viewing area. Hunters do not often experience this, because they are not on the scope long enough for it to matter unless they are spending a day at the range. Bench rest shooters experience this more, since they might be on the glass for many minutes before a shot. Tactical guys suffer with shit glass. When it comes to optics you get exactly what you pay for. Understanding that and buying exactly what you need for your chosen sport is important. A hunting hunting locally a few times a year can use a cheap $100 scope for decades. A guy who hunts a LOT and travels all over the country needs better, more reliable glass. A cop on an SRT might be on a scope for HOURS at a time and needs seriously clear optics. So putting a $1200 tactical scope on a deer rifle makes no sense. No more than putting a $300 scope on a police rifle. Pick the optic to fit your needs and as those needs grow, either in time on glass or in harsh environments, consider moving up the price scale.

    • It depends on the velocity and conditions and projectile, but I can give you generic numbers to get you started. I’ll use the Sierra 175 MK as the reference and give you velocity ranges. All numbers reflect the UP travel needed from a 100 yard zero. Keep in mind, these numbers are only accurate per the atmospheric conditions I enter into the program:
      2500 fps: 41.87 minutes
      2550 fps: 39.95 minutes
      2600 fps: 38.16 minutes
      2650 fps:36.81 minutes

      Those numbers reflect what is needed on a 55 degree day at around 400 foot elevation above sea level. On a 90 degree day, chances are the velocities would be higher so the required come-ups would be lower. At any rate, those numbers give a good estimate of what you would see with a 20 inch, 24 inch and 26 inch barrel. For instance, a 26 inch barrel with 43 grains of powder “X” would show around 2580 fps. Same barrel with 45 grains of “x” would show closer to the 2650 to 2670 fps range. As you can see, there are many factors that determine the final number. At any rate, if you know your rifle is shooting around 2550 fps with your chosen load, you would want to use a scope that had enough adjustment to allow you to dial up 40 minutes from Zero. So if your scope only had, say, 60 moa total adjustment, you would need to use a tapered base for the scope mount. Which would allow you to use more of the scopes internal adjustment for UP travel.

  3. Thanks, this article quite eloquently describes what I could not put into words, for some of my buddies, new into long range.
    Not that I am any good at it myself………
    On my 308 Howa I fitted what is supposed to be a 20 MOA Picatinny rail, for my Vortex Viper PST.
    I still had to shim the rail another 16 MOA, to fully use the turret adjustment out to 1000 meters.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s