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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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May 18th, 2009

Ruger Offers New SR-556 with Gas-Piston Upper

Ruger has jumped on the “black rifle” bandwagon. One of the more popular (and unexpected) product releases at the 2009 NRA Annual Meeting was yet another AR15-style rifle, Ruger’s new $2000.00 SR-556 carbine with gas-piston upper. For tactical applications the gas piston design is a good idea. It keeps vented gases away from the bolt/bolt carrier assembly, allowing the gun to run MUCH cleaner and cooler. This is something the U.S. military should have adopted 40 years ago, and in fact, the father of the M16, Gene Stoner, employed a gas piston on his Stoner 63 back in the ’60s. More recently Heckler & Koch (and other smaller companies) have developed gas-piston uppers for the AR platform. Ruger’s new SR-556 represents the first time a major American gun-maker has offered a complete AR-style rifle with the gas-piston technology.

Ruger SR-556 AR

CLICK HERE to watch Ruger SR-556 Video.

The Ruger SR-556 does offer some nice components, including a full-length Picatinny-style rail on top, folding Troy Industry battlesights, and a comfortable Hogue pistol grip. However the SR-556 still uses the common six-position adjustable AR stock, something we consider a poor design (the cheek weld is too low for use with scopes and the stock’s underside has many projections that can hang up on slings and gear). Doubtless Ruger will sell many SR-556 rifles to a market starved for AR-style inventory, but we wish Ruger had gone a step farther in design evolution and done more than just slap a piston upper and rails on a 40-year old design. We also wonder if many buyers will be deterred by the SR-556’s hefty $1995.00 (MSRP) price-tag.

CLICK HERE for Ruger SR-556 Spec Sheet (.pdf file).

Ruger SR-556 AR

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