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August 30th, 2012

Mirage Shields Tame Barrel Heat for More Accurate Shooting

Even if you don’t shoot competitively, you can benefit from having a mirage shield on your barrel. The shield helps prevent barrel heat from “cooking” the air in front of your scope, which can distort the view you see through the optic. Barrel heat creates a mirage effect that can blur the target image and actually shift your apparent aiming point up and down. Competitors know that a mirage shield helps them shoot smaller groups and better scores. Mirage shields can likewise benefit Varmint shooters on those hot summer groundhog and prairie dog expeditions.

Make a Mirage Shield from Discarded X-Ray Film
Forum member Fabian from Germany, whose Sako 6BR was featured as a Gun of the Week, has devised a clever and inexpensive mirage band option. Fabian is a radiologist by trade. He notes that many X-ray machines require a daily test film for calibration. These are normally just discarded in the trash, so you can get them for free.

mirage shield

Fabian explains: “I’m a radiologist, so I handle medical x-ray films every day. Modern X-ray machines use laser-based printers and they need to print a test-film every day. One x-ray film is about 43×35 cm (16.9″ x 13.7″). Made from polyester, the films are very stable and only 0.007″ inches thick. They are light-weight, semi-transparent, and very stable. Using normal scissors, you can easily cut four mirage shields from a single sheet of film. Then glue on some velcro to attach to your barrel. Try it, you will not be disappointed.”

mirage shield

More Do-It-Yourself Ideas
Other forum members have made mirage shields out of common, inexpensive materials such as old venetian blinds, thin plastic edging strips, and even cardboard reinforced with strapping tape. There’s no “magic material”. However many shooters have found that wider shields (extending well past the barrel sides) work better than narrow shields, particularly in hot weather.

Mirage Shields with Printed Designs
If you prefer to purchase a mirage shield, Shotmaster 10X offers a wide variety of shields starting at just $5.00 for a plain white 18″ shield. Patterned shields (including camo designs) are priced by length: $8.50 (18″), $9.50 (20″), $11.00 (24″). All Shotmaster shields come with two (2) velcro patches with self-stick adhesive.

Shotmaster 10X Mirage Shield

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May 18th, 2009

USAMU Teaches Wind-Reading on ShootingUSA May 20th

Mark your calendars for Wednesday, May 20th, when a “must-watch” episode of ShootingUSA television is broadcast. On the 20th, Sergeant Grant Singley and other members of the USAMU Service Rifle Team explain wind-reading for long range competition. This should be a very informative segment, enhanced with on-screen graphics illustrating key points.

Sgt. Singley notes: “A 5-mph crosswind at 600 yards will move an 80gr .223 bullet about 15 inches. You can see that being able to accurately read the wind will greatly enhance your success on the rifle range.” The USAMU uses a clock method to estimate wind value based on the direction. Then you add in the measured (or estimated) velocity for the vector value (wind strength and angle).

Sgt. Singley recommends the use of a wind meter, such as a Kestrel, to gauge wind speed. But observed conditions will also indicate wind velocity. Sgt. Singley explains: “Zero-to-three mph, is hardly felt on the shooters face, but smoke will drift. Three-to-five mph is felt lightly on the shooter’s face. Five-to-eight mph keeps leaves in constant movement. Eight-to-12 mph will blow dust and loose paper, and 12-to-15 mph winds cause small trees to sway.”

Using Mirage to Estimate Wind Speed and Direction
Long-range shooters also need to learn how to read mirage. Mirage is the reflection of light through layers of air that have a different temperature than the ground. These layers are blown through by the wind, and can be monitored through a spotting scope, to detect direction and speed. You can see what appear to be waves running across the screen. This is the mirage. The waves appear to be running right to left, which indicates a wind coming out of the right. To clearly see the mirage through a spotting scope, you bring the target into focus, then adjust the focus about a quarter turn counter-clockwise.”

Graphics copyright 2009 ShootingUSA, used with permission.

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