November 2nd, 2013
Many folks struggle when they sight-in a scoped rifle for the first time. A very common mistake is clicking the turrets in the wrong direction. That’s frustrating and it wastes ammo. Another common problem occurs when people sight-in at a distance other than 100 yards. People sometimes struggle to figure out how many clicks they need to correct point of impact if they’re zeroing at 200, 250, or 300 yards.
To make the sight-in process more fool-proof, AccuScope has released two handy Apps for smart phone users. Whether used for initial sight-in or in-the-field adjustments, these smartphone Apps can get you zeroed quickly and reliably.
Using the Apps is easy. First, boresight the gun to get on paper. After the gun is fouled-in (so it is shooting normally) shoot a carefully aimed 3-shot group. Then go to the target and measure the vertical and horizontal distance from the 3-shot group center to your aiming point. Input those numbers into the App, along with your sight-in distance (from muzzle to target). The App then calculates exactly how many elevation and/or windage clicks you must crank into your scope to move point-of-impact to point of aim. Put in the specified clicks and then take a fourth shot to confirm your zero. The fourth shot should impact right on your point of aim (within the limits of the gun’s inherent accuracy.)
Given Murphy’s Law, a shooter can still mess things up if he inputs left clicks when the App calls for right clicks, or inputs down clicks when he needs up clicks. But as long as you look at the “R/L” and “Up/Down” labels on your turrets before spinning the knobs, you shouldn’t have any problems.
AccuScope is available in two versions, Standard and Premium. The $4.99 Standard version works for 1/4 MOA-click-value scopes. The $9.99 Premium version works with all scopes and any click values. The Premium version works with 1/8 MOA clicks, 1/4 MOA clicks, Metric clicks, or Milrad segment click values. So, if you have a scope with 1/8 MOA clicks, you’ll need the Premium version.
AccuScope iPhone Apps are available through Apple’s App Store: Standard | Premium
AccuScope Android Apps are available through the AppBrain Store: Standard and Premium
Product Tip by EdLongrange. We welcome reader submissions.
Editor’s Comment: Does this App really provide a solution you can’t figure out yourself with simple arithmetic? No, but some math-challenged guys may find that the App prevents errors. Additionally, following the step-by-step process used by the App will probably help some shooters avoid confusion, and avoid wasting ammo clicking in the wrong directions.
Note however, that there is an even simpler way to zero, if you have a very solid front and rear rest that will hold the gun absolutely steady while you click. After bore-sighting, fire a couple rounds (with the same point of aim). Then place the rifle so the center of the cross-hairs is exactly on your original point of aim. Next, without disturbing the gun in any way, dial your turrets so that the center of the cross-hair moves over the center of your group. That’s it. You’re now zeroed (though you may want to repeat the process for confirmation). Again, this only works if the gun doesn’t shift one bit when you’re clicking. Having a helper steady the gun as you click the turrets will make this “no-math” method work more effectively.
Click-to-Initial POI Zeroing Method Demonstrated
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October 18th, 2013
Based on its external appearance, a modern riflescope may seem simple. It’s just a tube with two or three knobs on the outside right? Well, looks can be deceiving. Modern variable focal-length optics are complex systems with lots of internal parts. Modern scopes, even ‘budget’ optics, use multiple lens elements to allow variable magnification levels and parallax adjustment. We had a chance to look inside a riflescope thanks to a product display from ATK, parent of Alliant Powder, CCI, Federal, RCBS, Speer, Weaver Optics. ATK sliced open a Weaver Super Slam scope so you can see the internal lens elements plus the elevation and windage controls. We thought readers would like to see the “inner workings” of a typical modern rifle scope, so we snapped some pictures. The sectioned Super Slam scope was mounted inside a Plexiglas case, making it a bit hard to get super-sharp images, but you can still see the multiple lenses and the complex windage and elevation controls.
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October 7th, 2013
Here’s a new scope that may be well-suited for short-range varmint hunting (for smaller critters) and for rimfire tactical matches. Bushnell has released a new, affordable 2-7x32mm variable rifle scope with a Bullet Drop Compensating (BDC) reticle configured for the .22 LR rimfire cartridge. Anyone who has shot the .22 LR past 50 yards knows that this round drops a lot in a short distance. The “Drop Zone” BDC reticle, with multiple aiming points out to 125 yards, helps you stay on target. The reticle is calibrated for 38-40 grain, .22 LR high-velocity loads, with a 50-yard zero. This new scope, part of Bushnell’s AR line of scopes, features a 1″ main tube, target-style turrets, and side-focus parallax adjustment. MSRP is $149.99, but web vendors have lower prices. Amazon.com sells the scope for $131.23 with free shipping for Prime Members.
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October 6th, 2013
Carl Zeiss Sports Optics is extending its ZEISS/Kenton Industries Custom Turret Promotion through December 31, 2013. Through this special offer, when you purchase a new CONQUEST HD5 Riflescope, you get one of two Kenton Custom Turrets calibrated for your specific load — either a LR Hunter Turret or Speed Dial Turret. Eligible scope models are the Zeiss CONQUEST HD5 3-15×42 #20 reticle with Lockable Target Turret, and the CONQUEST HD5 5-25×50 #20 reticle with Lockable Target Turret. The retail value for the free custom elevation turret is $125.00
Mike Jensen, President of Carl Zeiss Sports Optics USA explains how the system works:
“With our custom turret system, [just] set the dial to the number 4 for 400 yards and you’re done. No complicated math, and no color codes to compensate for the bullet drop. The numbered markings on the custom turret by Kenton Industries are easy to read and intuitive. Add the available ‘no-hold-over’ PLEX reticle with the Kenton custom target turret and you have an extremely accurate and very robust long-range shooting setup.”
To receive a free ZEISS/Kenton Custom Ballistic Turret, the qualifying CONQUEST HD5 Riflescopes must be purchased from an authorized ZEISS dealer before December 31, 2013. Offer details and order forms can be found at Kentonindustries.com or at www.zeiss.com/sports. The order form requires ballistic info such as cartridge, ammunition type, bullet weight, and zero range. The custom turret will be shipped within 2-3 weeks. This offer is valid for U.S. customers only.
For more information on ZEISS products visit www.zeiss.com/sports or the Zeiss Facebook Page.
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October 5th, 2013
In this NSSF video, Ryan Cleckner shows how to set up a scope on a tactical or hunting rifle. Ryan, a former U.S. Army Sniper Instructor, notes that many shooters spend a small fortune on equipment, but fail to set up their rifle to use the optics optimally. Cleckner likens this to someone who owns an expensive sports car, but never adjusts the seat or the mirrors.
Ryan notes that you want your head and neck to be able to rest naturally on the stock, without straining. You head should rest comfortably on the stock. If you have to consciously lift your head off the stock to see through the scope, then your set-up isn’t correct. Likewise, You shouldn’t have to push your head forward or pull it back to see a clear image through the scope. If you need to strain forward or pull back to get correct eye relief, then the scope’s fore/aft position in the rings needs to be altered. Watch the full video for more tips.
Tips on Mounting Your Scope and Adjusting Your Comb Height:
1. Normally, you want your scope mounted as low as possible, while allowing sufficient clearance for the front objective. (NOTE: Benchrest shooters may prefer a high mount for a variety of reasons.)
2. Once the scope height is set, you need to get your head to the correct level. This may require adding an accessory cheekpad, or raising the comb height if your rifle has an adjustable cheekpiece.
3. Start with the rifle in the position you use most often (standing, kneeling, or prone). If you shoot mostly prone, you need to get down on the ground. Close your eyes, and let you head rest naturally on the stock. Then open your eyes, and see if you are too low or too high. You may need to use a cheekpad to get your head higher on the stock.
4. If your scope has a flat on the bottom of the turret housing, this will help you level your scope. Just find a flat piece of metal that slides easily between the bottom of the scope and the rail. Slide that metal piece under the scope and then tilt it up so the flat on the bottom of the scope aligns parallel with the flats on the rail. Watch the video at 8:40 to see how this is done.
Video find by EdLongrange. We welcome reader submissions.
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August 20th, 2013
Burris Signature Rings with polymer inserts are an excellent product. The inserts allow you to clamp your scope securely without ring marks. Moreover, using the matched offset inserts you can “pre-load” your scope to add additional elevation. This helps keep the scope centered in its elevation range while shooting at long range. Additionally, with a -20 insert set in the front and a +20 insert set in the rear, you may be able to zero at very long ranges without using an angled scope base — and that can save money. (To move your point of impact upwards, you lower the front of the scope relative to the bore axis, while raising the rear of the scope.)
Insert Elevation Values and Ring Spacing
People are sometimes confused when they employ the Burris inserts. The inset numbers (-10, +10, -20, +20 etc.) refer to hundredths of inch shim values, rather than to MOA. And you need the correct, matched top/bottom pair of inserts to give you the marked thousandth value. Importantly, the actual amount of elevation you get with Burris inserts will depend BOTH on the insert value AND the spacing between ring centers.
Forum member Gunamonth has explained this in our Shooters’ Forum:
Burris inserts are [marked] in thousandths of an inch, not MOA. To know how many MOA you gain you also need to know the ring spacing. For example, with a -20 thou insert set in the front and a +20 thou insert set in the rear, if the ring spacing is 6″, the elevation change will be approximately +24 MOA upwards.
Here’s how we calculate that. If you have a 2 X 0.020″ “lift” over a distance of 6 inches (i.e. 0.040″ total offset at 0.5 feet) that’s equivalent to 0.080″ “lift” over 12 inches (one foot). There are 300 feet in 100 yards so we multiply 0.080″ X 300 and get 24″ for the total elevation increase at 100 yard. (Note: One inch at 100 yards isn’t exactly a MOA but it’s fairly close.)
Here’s a formula, with all units in inches:
Total Ring Offset
——————– X 3600 = Change @ 100 yards
(.020 + .020)
—————– X 3600 = 24 inches at 100 yards
NOTE: Using the above formula, the only time the marked insert offset will equal the actual MOA shift is when the center to center ring spacing is 3.60″. Of course, you are not required to use 3.60″ spacing, but if you have a different spacing your elevation “lift” will be more or less than the values on the inserts.
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July 31st, 2013
When shopping for a new riflescope or spotting scope it’s easy to get confused by all the technical terminology. Do you wish you had a better way to compare scopes — beyond just size, weight, and price? Well Swarovski Optik can help. The Swarovski Hunting Blog offers a helpful guide to technical terms used when comparing scope specifications. Here are some important definitions, expressed in layman’s language:
Objective Lens Diameter
The objective lens diameter determines the size of the optical system’s entrance pupil. The bigger the objective lens diameter, the more light the system can capture. However, the size of the objective lens does not determine the size of the field of view.
The size of the Exit Pupil is determined by the objective lens diameter and the magnification. If you look at the eyepiece from a distance of around 30 cm (11.8 in), the Exit Pupil appears as a bright disc.
For calculating the Exit Pupil the formula is:
Exit Pupil = objective lens diameter ÷ magnification (expressed in power number).
The larger the Exit Pupil, the more light will reach the eye.
Field of View
The Field of View is the size of the circular section of the area which can be observed when you look through a long-range optical device. In the case of rifle scopes, it is specified at a distance of 100 meters or 100 yards. For example, 42.5 m at 100 m or 127.5″ at 100 yards. As an alternative, the Field of View can also be stated in degrees (e.g. 6.6°).
NOTE: The technically-feasible size for the Field of View is essentially determined by the magnification. The higher the magnification the smaller the Field of View.
The Twilight Factor defines the optical system’s performance in poor light. The statement “the greater the twilight factor, the better the suitability for twilight” only applies if the exit pupil is larger than or at least as big as the eye’s pupil. The pupil in the human eye can only open to around 8 mm. As we get older, our eyes become less flexible, which limits our ability to see things in twilight or at night. Therefore [an optic's] exit pupil cannot always be fully utilized.
For calculating the Twilight Factor the formula is:
Twilight Factor = root of ( magnification x objective lens diameter ).
NOTE: Spotting scopes have extremely high twilight factors because of their high magnification and large objective lens diameter. But [when used at high magnification] their small exit pupil can make them [somewhat difficult] to use in twilight.
CLICK HERE to Read Full Article (with more illustrations).
Photos copyright Swarovski Optik Blog, all rights reserved.
Story Tip by EdLongrange. We welcome reader submissions.
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July 31st, 2013
Forum member Jacob spotted this simple, but effective set of scope ring inserts on the Brownells Website. With these inserts, you can use a scope with 1″-diameter main tube in 30mm rings. Non-marring, matte black Delrin sleeves surround the scope tube so it can fit larger-diameter rings. Each sleeve comes in two parts for easy installation around your scope tube. This way you can use the same 30mm rings for all your scopes.
Ring Reducers are sold as front/rear kits. Cost is just $19.99 for the 1″ to 30mm converters, item 084-000-091. There are also sets that reduce 30mm rings to 25mm, and 1″ rings to 3/4″ or 7/8″.
Note: These Brownells units simply function as plastic bushings. Unlike Burris Signature Ring inserts, they do not allow you to “pre-load” windage or elevation. If your rings are misaligned, the Brownells Ring Reducers won’t correct that problem.
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July 9th, 2013
If you need a riflescope at a bargain-basement price, Natchez Shooters Supply (Natchez) is running a big sale on Weaver Scopes right now. You’ll find huge savings on scopes big and small, ranging from a 1.5-4.5x24mm all the way up to an 8-32x50mm. The discounts off MSRP are really pretty remarkable. For example, a Wever 6-24x50mm Classic Extreme Scope with illuminated reticle (and 30mm tube) is now just $339.95, marked down from $579.00. (That’s a 41% price cut). The Weaver 2.5-10x56mm Classic Extreme scope, a good general-purpose 30mm-tube hunting scope, is marked way down to $299.95. Original MSRP on this scope was $926.88, and it sells elsewhere for over $550.00. Most of these scopes are discontinued models, but they still carry the normal Weaver warranty.
Scope Sale tip from EdLongrange. We welcome reader submissions.
NOTE: to find particular on-sale models, we suggest you type “Weaver” plus the scope power description in the Natchez home page search field. For example, type “Weaver 2.5-10×56″. That should bring up the item with the low sale price.
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April 13th, 2013
Hunters and tactical shooters need scopes with good low-light performance. For a scope to perform well at dawn and dusk, it needs good light transmission, plus a reasonably large exit pupil to make maximum use of your eye’s light processing abilty.* And generally speaking, the bigger the front objective, the better the low-light performance, other factors being equal. Given these basic principles, how can we quickly evaluate the low-light performance of different makes and models of scopes?
Here’s the answer: ScopeCalc.com offers a FREE web-based Low-Light Performance Calculator that lets you compare the light gain, perceived brightness, and overall low-light performance of various optics. Using this scope comparison tool is pretty easy — just input the magnification, objective diameter, exit pupil size, and light transmission ratio. If the scope’s manufacturer doesn’t publish an exit pupil size, then divide the objective diameter in millimeters by the magnification level. For example a 20-power scope with a 40mm objective should have a 2mm exit pupil. For most premium scopes, light transmission rates are typically 90% or better (averaged across the visible spectrum). However, not many manufacturers publish this data, so you may have to dig a little.
ScopeCalc.com’s calculator can be used for a single scope, a pair of scopes, or multiple scopes. Once you’ve typed in the needed data, click “Calculate” and the program will produce comparison charts showing Light Gain, Perceived Brightness, and Low-Light Performance. In the example below, we compared a “generic” 5-18×50 Tactical scope with a “generic” 8-32 Benchrest scope.
Though the program is easy to use, and quickly generates comparative data, assessing scope brightness, as perceived by the human eye, is not a simple matter. You’ll want to read the annotations that appear below the generated charts. For example, ScopeCalc’s creators explain that: “Perceived brightness is calculated as the cube root of the light gain, which is the basis for modern computer color space brightness scaling.” In addition, the way ScopeCalc measures Low-Light Performance is pretty sophisticated: “Low Light Performance [is calculated] as the average of light gain and resolution gain through magnification, as a measure of target image acuity gain in low light similar to Twilight Performance specified by scope manufacturers. Low Light Performance calculated here is much more useful than Twilight Performance, as Twilight performance is the average of the just the objective lens diameter times magnification, while Low Light Performance is the average of the actual Perceived Brightness times magnification, which also includes the exit pupil/eye pupil relation, light transmission, approximated diffraction, as well as the perception of relative light gain. Just as with Twilight Performance, this Low Light Performance calculation does not yet include lens resolution and contrast as factors. Therefore lower quality optics will yield relatively less gains at higher magnifications.” Got that?
*In low light, the human eye can typically dilate to 5mm – 7mm. The exact amount of dilation varies with the individual, and typically declines, with increasing age, from 7mm (at age 20) to a dark-adapted pupil of about 5.5mm by age 65. To take full advantage of a scope’s light-gathering capacity, the diameter of an eyepiece exit pupil should be no larger than the max diameter of your eye’s dark-adapted pupil, so that all of the light collected by the scope enters your eye, rather than falling on the iris. A large 8mm exit pupil may seem good, but it would be partly “wasted” on a shooter in his 60s.
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March 24th, 2013
Nikon has introduced an all-new line-up of affordable riflescopes for hunters and varmint shooters. The new Nikon ProStaff 5 Series of scopes feature four times zoom range and a bright new optical system. With their fully multi-coated lenses, ProStaff 5 riflescopes provide up to 95% light transmission. That’s great for hunters working at dawn and dusk. (Some ProStaff 5s also have illuminated reticles). All ProStaff 5 scope models are waterproof, fogproof, and shockproof.To View ProStaff 5 Scopes, Click this Link and then SORT by “NEWEST” in display.
The ProStaff 5 line-up of scopes ranges from 2.5-10X to 4.5-18X with a variety of reticle options including NikoPlex, BDC, Fine Crosshair with dot, and Mil-Dot. Some ProStaff 5 scopes have an illuminated reticle with five intensity levels of red or green. A rheostat dimmer is located on the side focus knob for easy adjustment. All ProStaff 5 scopes now offer spring-loaded, instant zero-reset turrets. This makes your return-to-zero fast and foolproof in the field. (To set your zero, just sight-in as usual, then lift the spring-loaded adjustment knob, rotate to “zero,” and re-engage.)
ProStaff 5 series scopes were designed with a constant (and generous) four inches of eye relief. If you’ve ever had to move your head back and forth as you changed magnification levels, you know that constant eye relief is a big deal with very real practical benefits in the field. The new ProStaff 5 scopes also feature a quick-focus eyepiece, to allow any shooter to easily bring the reticle into focus.
Nikon ProStaff 5 Scopes
|Part # Model Reticle MSRP
6735 2.5-10×40 Nikoplex $269.95
6736 2.5-10×40 BDC $279.95
6737 2.5-10×40 (silver) BDC $289.95
6738 2.5-10×50 Nikoplex $369.95
6739 2.5-10×50 BDC $379.95
6740 3.5-14×40 SF Nikoplex $349.95
6741 3.5-14×40 SF BDC $359.95
6742 3.5-14×40 SF (silver) BDC $369.95
6743 3.5-14×40 SF Mildot $359.95
6744 3.5-14×50 SF Nikoplex $449.95
|Part # Model Reticle MSRP
6745 3.5-14×50 SF BDC $459.95
6750 3.5-14×50 SF Illuminated Nikoplex $569.95
6751 3.5-14×50 SF Illuminated BDC $579.95
6746 4.5-18×40 SF Nikoplex $449.95
6747 4.5-18×40 SF BDC $459.95
6748 4.5-18×40 SF Mildot $459.95
6749 4.5-18×40 SF Fine Crosshair with Dot $459.95
6752 4.5-18×40 SF Illuminated BDC $579.95
6753 4.5-18×40 SF Illuminated Nikoplex $569.95
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March 21st, 2013
Mirage shields really do help you hit your targets more reliably. Novice shooters may wonder “Why does that guy have a venetian blind attached to his barrel?” Here’s why. As the barrel gets hot, the heat from the barrel rises up, cooking and distorting the air directly in front of the scope’s front lens. In essense, the rifle creates its own nasty visual mirage, right in the worst possible place. You can have a $4000.00 custom rifle and a $2500.00 scope but if the air in front of your scope is distorted, it can literally move your apparent point of aim on the target relative to your cross-hairs, causing you to miss the shot.
As our friend Boyd Allen observed: “Varminters should use mirage shields. Think about it. You’ve invested thousands of dollars in a fancy varmint rifle and quality scope. You may have spent hundreds of dollars traveling to the varmint fields and spent dozens of hours loading up your ammo. Without a mirage shield on your barrel, once that barrel gets hot, you WILL get mirage effects that can make you miss a shot.”
So, we’ve established you need a mirage shield to shoot your best when the barrel gets hot. You can make your own shield from a scrap blind, or purchase a ready-made plastic or aluminum shield. Sinclair Int’l offers 2″-wide, white mirage shields in 18″ (#06-7200) or 24″ (#06-7300) lengths for $4.95. Shotmaster 10X offers a variety of Patterned Mirage Shields, starting at $6.00. These include a Patriotic theme and even Tiger Stripes:
Camo Mirage Shields for Tactical Shooters and Hunters
Though tactical shooters should use mirage shields for long-distance, slow-fire stages, for the most part, tactical shooters don’t bother. One reason is that mirage shields CAN detach if you’re crawling around in the bush. However, for many tactical shooting situations, a mirage shield IS both practical and recommended. And now, for the first time, tactical shooters can get mirage shields in camo patterns to match their rifles. These camo shields should also be popular with varminters and long-range hunters.
At the request of AccurateShooter.com, Shotmaster 10X created a line of camo-pattern mirage shields (see above). Made of 2″-wide aluminum strips, these are available in 18″, 20″, and 24″ lengths. The camo-pattern shields come complete with Velcro attachments, and start at $8.50 for the 18″ length. The 20″ models are $9.50, while 24″ shields are $11.00.
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