User Posts: Chris 'The Optics Nut'

Brand/Model: Bushnell PrimeMagnification Range: 4-12XObjective Lens Size: 40 mmLength/Weight/Tube Diameter: 12.8"/18.6 oz/1 inReticle Info: ...

Brand: BushnellModel: NitroMagnification: 10x (fixed)Objective Lens: 42 mmExit Pupil: 4.2 mmEye Relief: 17 mmField of View: 340 ft/1000 yardsHeight: ...

Model: Prime 1300 5x20Distance Range: 5-1300 yardsMagnification: 5X 20mm objective lensMeasuring System: Yards/MetersAngle Compensation: YesWaterproof: ...

Are you stressing about which system you want on your new scope? Not sure about the differences between the two? Will your choice make a huge ...

What does MOA mean in shooting? We explain Minutes of Angle and provide tips to using it to adjust for bullet drop.

Do you avoid mil dot reticles because you don't know how to use them? Does magnification matter with a mil-dot scope? And, no, Mil does not stand ...

After field testing the Maven RS.1 rifle scope, this may be our new favorite optics brand. Find out why right here!

We field tested the 10x42 Maven C1 binoculars and the results are in. Find out why these are the ultimate bino to 'get you more for less'.

We put the Everglade spotting scope by Carson through its paces and the 15-45x60mm optic did not disappoint. Check it out now!

These Droptine 10X42 binoculars are new to 2017. Will you jump on the Burris bino bandwagon? Read our field test then decide!

Browsing All Comments By: Chris 'The Optics Nut'
  1. Reply
    Chris 'The Optics Nut' August 22, 2020 at 11:23 pm

    Hi David, the RS.1 is 24.5oz (694.5g).

  2. Great question! Bullet drop can easily be calculated with a ballistics calculator. There, you can input information about your specific rifle setup, load info, and atmospheric/climate conditions to acquire specific numbers.

    If you want to do the math yourself, it will require getting out to the range and seeing how far off bull’s-eye you are when you shoot at 200 yards. The formula for calculating bullet drop at 200 yards is the same for calculating bullet drop at any distance: bullet drop / mil size for that distance = mils needed to adjust. Of course, there may be some minor tweaks due to factors out of your control. Use the most appropriate adjustment to zero your scope. 200 yards is a good zero! Hope this info helps.

  3. Jim, the formula the manufacturer provided is perplexing to me as I’m not familiar with a “variable” constant (oxymoron?) based on magnification even though I can see your thought process. Like you have determined, it is customary to use target size (m) x 1000/target MIL size = target distance (m). The way I understand it is, 1000 is the constant because one unit (milliradian) will be representative of 1/1000th of a radian. This rule is true regardless of the magnification of your scope. We must remember that mils are an angular measurement and not linear.

    If you’ve identified that you have a second focal plane rifle scope, you can only use it at one power setting for accurate ranging and holding over. This is usually max power unless the manufacturer has specified otherwise, and in your case, it may very well be 9x. However, the formula with the 1000 constant remains the same. Hope this helps to clear up any confusion. Thank you for reaching out and sharing your kind thoughts.

  4. Todd, thank you for your kind feedback. It’s not an easy topic to wrap your head around when you’re new to MRADS, and even with experience as you have, it can be difficult to present this information in a concise and easy-to-understand manner. We squeezed a good amount of “learning” onto one page, and we are glad that we can provide some basic understanding of MRADs.

  5. James, thanks for the comment – that’s not a bad idea. Turret tracking and accuracy is essential and using a truth stick can be telling. I have not used one myself, but it may be a good excuse to put some turrets and manufacturer claims to the test using this method.

  6. Hi Erik, I'm glad you enjoyed the article! Thank you for pointing out what seems to be a math discrepancy as it does get confusing when you're converting linear measurements and trying to see how it works with angular measurements. In short, while 3.6" does in fact equal 9.144 centimeters, we're not necessarily comparing or converting the inch measurement to the centimeter measurement. What we are trying to do is find what the linear measurement is for a mil remembering that mils are an angular measurement.

    Since we are talking about angular measurement, the centimeter measurement will always be slightly larger than the inch measurement with the same mil adjustment. Why? Because 100 meters is actually equal to 109.361 yards. So, each click (say, with a 1/10th turret) will always be one click, but how you measure it in linear terms will be different since 100 meters is not equal to 100 yards. When it comes down to it, 1/10th of a mil is actually equal to .9999 centimeters - it's far more practical to say 1 cm. With this in mind, it will take 10 MIL clicks on a 1/10th MIL turret to make a full 1 MIL adjustment for 10 centimeters at 100 meters.

    It's easier if you don't get tied up in the math between the conversions from inches to centimeters and vice versa. It's much better to learn the system you do best with remembering that things could change when you actually get to shooting. The wind, your particular rifle, and other factors can affect bullet impact. In no time, you'll see how easy it is to put linear measurement aside and start making or calling corrections in mils using your reticle. Happy shooting friend!

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