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August 18th, 2007
 Here’s something that can save you lots of time and aggravation on a varminting trip. This little $60 gizmo is great for varmint hunters and any one who needs to make a quick shot in shifty wind conditions. Kenton Industries’ Tuned Windage Compensator (TWC) has built-in windage marks for 10 mph cross-winds at 100-1000 yards. How do they do that? Well the knobs are calibrated either for specific calibers/loads, or they can make custom knobs using your observed field data. The knobs can compensate for various wind speeds (2-20 mph) and angles (15°- 90°), by applying some simple conversion ratios. For example, this is how you’d set the knob for a 5 mph wind or a quartering wind: 5 mph crosswind at 400 yards = dial in 200 yards; 10 mph, 45° crosswind at 400 yards = dial in 300 yards.
August 16th, 2007
Danny Reever recently researched the options for shooters who need corrective lenses. Danny writes: “My eyes were checked last week, and I needed a new prescription. After doing some online research, I received an email from a fellow shooter who happens to be an optician. He gave me sound advice and technical facts and figures. My local optician later concurred with everything the fellow shooter/optician suggested. Here are the key things I learned:
 CHOICE of MATERIALS
Shooting glasses need to be shatterproof. You basically have only two choices in shatterproof materials: Polycarbonate, or Trivex™ made by PPG. Most optical shops will favor Polycarbonate, because that’s what they sell the most of. However Poly is far from the best material in terms of optical properties. Glass is the best for optical clarity and lack of distortion, with an ABBE number of about 58 (the measurement of chromatic aberration, higher being better). Unfortunately glass lenses are heavy, (glass has a Specific Gravity number of about 2.50–the higher number the more weight). Worse yet, glass shatters. With conventional glass lenses, if a cartridge lets go at 60,000 PSI, you could lose an eye, or worse.
Polycarbonate is very strong and shatter resistant. Unfortunately it only has an ABBE number of 30. This is not great optically, especially when you are looking off-axis. Poly, however, is much lighter than glass. Poly has a Specific Gravity number of about 1.20.
So that leaves PPG Trivex™. Trivex is very strong AND very light, and rates well optically. Trivex™ is nearly as strong as Polycarbonate, yet is even lighter (with a Specific Gravity of 1.11). With an ABBE number of about 45, Trivex™ is much better optically than Polycarbonate. In addition, Trivex™ is chemically resistant to cleaning solutions, oil, and skin care products. Trivex™ can be drilled, grooved and notched very easy, so it is well-suited for rimless glasses and sport glasses. Click for TriVex Lens Report.
LENS COATINGS and FEATURES
I was told to go with a very high-quality, anti-reflective coating. I also ordered ‘Transitions’ photochromatic coating to eliminate the need for extra sunglasses. (However, a ‘Transitions’ coating may not work well as driving glasses since most automobile windshields are tinted to block the UV rays that trigger the transitions effect.)
I ordered a no-line bifocal. This was a compromise in itself since having a single focal plane for shooting might be a better bet, but then you may be forced to buy two pairs of glasses. Your lens prescription can also be optimized for scope-viewing by having the viewing axis ground off-center. But then again you may need a second pair for everyday use.
CONCLUSION
The experts told me that, as far as eyeglasses are concerned, ‘Everything in optics is a trade-off…there is NO perfect answer’. Pick a good licensed optician that is familiar with ALL the options available to you. Do not deal with a ‘frame stylist’ unless being trendy or pretty is your only goal. The fellow shooter/optician gave me this advice: ‘Good opticians, like good gunsmiths, are not cheap in the short run, but always cheaper long term’. Remember, you only have one pair of eyes, so protecting them must be the first priority (remember the trade offs), otherwise you are playing ‘Russian Roulette’ every time you pull the trigger.”
August 13th, 2007
Let’s say you’ve purchased a new scope, and the spec-sheet indicates it is calibrated for quarter-MOA clicks. One MOA is 1.047″ inches at 100 yards, so you figure that’s how far your point of impact (POI) will move with four clicks. Well, unfortunately, you may be wrong. You can’t necessarily rely on what the manufacturer says. Production tolerances being what they are, you should test your scope to determine how much movement it actually delivers with each click of the turret. It may move a quarter-MOA, or maybe a quarter-inch, or maybe something else entirely. (Likewise scopes advertised as having 1/8-MOA clicks may deliver more or less than 1 actual MOA for 8 clicks.)
 Reader Lindy explains how to check your clicks: “First, make sure the rifle is not loaded. Take a 40″ or longer carpenter’s ruler, and put a very visible mark (such as the center of an orange Shoot’N’C dot), at 37.7 inches. (On mine, I placed two dots side by side every 5 inches, so I could quickly count the dots.) Mount the ruler vertically (zero at top) exactly 100 yards away, carefully measured.
Place the rifle in a good hold on sandbags or other rest. With your hundred-yard zero on the rifle, using max magnification, carefully aim your center crosshairs at the top of the ruler (zero end-point). Have an assistant crank on 36 (indicated) MOA (i.e. 144 clicks), being careful not to move the rifle. (You really do need a helper, it’s very difficult to keep the rifle motionless if you crank the knobs yourself.) With each click, the reticle will move a bit down toward the bottom of the ruler. Note where the center crosshairs rest when your helper is done clicking. If the scope is accurately calibrated, it should be right at that 37.7 inch mark. If not, record where 144 clicks puts you on the ruler, to figure out what your actual click value is. (Repeat this several times as necessary, to get a “rock-solid”, repeatable value.) You now know, for that scope, how much each click actually moves the reticle at 100 yards–and, of course, that will scale proportionally at longer distances. This optical method is better than shooting, because you don’t have the uncertainly associated with determining a group center.
Using this method, I discovered that my Leupold 6.5-20X50 M1 has click values that are calibrated in what I called ‘Shooter’s MOA’, rather than true MOA. That is to say, 4 clicks moved POI 1.000″, rather than 1.047″ (true MOA). That’s about a 5% error.
I’ve tested bunches of scopes, and lots have click values which are significantly off what the manufacturer has advertised. You can’t rely on printed specifications–each scope is different. Until you check your particular scope, you can’t be sure how much it really moves with each click.
I’ve found the true click value varies not only by manufacturer, but by model and individual unit. My Leupold 3.5-10 M3LR was dead on. So was my U.S.O. SN-3 with an H25 reticle, but other SN-3s have been off, and so is my Leupold 6.5-20X50M1. So, check ‘em all, is my policy.”
August 11th, 2007
Those who are far-sighted, and older shooters with presbyopia, may have difficultly focusing on close objects. At the range, this may make it difficult to read range cards, printed come-up tables, or even the “fine print” found in manuals for chronographs and othershooting accessories. The instructions for this writer’s chronograph are sufficiently obtuse and hard-to-remember that I always bring the operator’s manual to the range. But if I can’t read the print, having the instructions won’t help.
Here’s a solution for shooters who need better close-up vision. Magellan’s sells stick-on inserts that mount to any glass or plastic lenses. Water is the adhesive–the surface tension effect of H20 is enough to keep the lens inserts in place. But this also lets you easily move the magnifying lenses from one set of glasses to another. These Optx 20/20 Lenses, Magellan’s Item #BA726, cost $24.85. Magellan’s notes: “Flexible Optx 20/20 lenses hold fast by their own molecular attraction (no adhesive needed) and can be peeled off and reattached many times.”
July 30th, 2007
 ShooterReady.com offers an excellent computer simulation that lets you “shoot” three different calibers at virtual ranges out to 2000 yards–complete with sound effects and realistic scenery. You view the target through a 10-20x zoom scope and adjust windage and elevation as with a real scope. A FREE Online Demo is available that lets you practice with a 175gr .308, and also Windrunner .338 and .50 BMG. Atmospheric conditions and range distance change with each stage, so there is plenty of challenge. Warning–if you’re at work, this can be addictive once you get the hang of it.
 You can practice Mil Dot ranging on 3 targets: A 12″ X 12″ swinging plate, a 30″ X 18″ knock-down plate, and a regulation 72″ X 19″ knock down plate. Each caliber has 70 range exercises, plus an advanced stage with 25 timed hold-offs, and moving targets.
The CD also includes “Interactive Classrooms” that teach you how to use Mil-Dot scopes and how to use a range card. The presentation on reading Mils and calculating target distances is very well done. It is much easier to learn interactively than by just reading a static manual. Below is a screenshot from the Mil-Dot Ranging “Classroom”.
Trust us, you can learn a great deal from the Free Demo. This is not just a shooter video game. The demo offers a variety of scenarios–enough to keep you occupied for quite some time. If you want to learn more, the full CD, with hundreds of scenarios, and five bonus stages, costs $39.95 from ShooterReady.com.
July 24th, 2007
In this video by Dan Lilja, you can see the difference between a factory barrel and a hand-lapped custom barrel with your own eyes. The borescope reveals the tooling marks, rough surface, and flaws in the lands that are not uncommon in a factory barrel. Conversely, the custom barrel (shown in the image below), shows sharp lands, a smooth surface (without excess machining marks), and rifling without scratches or cuts. If you haven’t watched this video before, you may be amazed.
You can learn more about borescopes by reading the Hawkeye Borescope Review by top UK shooter Vince Bottomley. Vince put a Hawkeye unit through its paces and concludes that it is an invaluable tool for diagnosing barrel problems and monitoring barrel wear. Vince writes: “With a borescope, you can tell immediately if your cleaning regime is effective, or inspect for throat-erosion and the general condition of the rifling. In addition, I have found that it is very useful for inspecting newly-cut chambers–making sure they are free from scoring and other machining defects and you can even have a good look at the muzzle-crown from the inside–one of the most important parts of any barrel. Tiny burrs can often be present on newly-cut crowns and even the most minute damage to a crown (often caused by careless cleaning) can play havoc with accuracy. For the professional gunsmith, you could say that a borescope is the equivalent of a doctor’s stethoscope.”
July 8th, 2007
Stephen Ivey has engineered an interesting set of gimbaled scope rings allowing up to 150 Minutes of Angle (MOA) of elevation. These rings have precision hinge pins front and rear allowing the entire scope to be tilted by a micrometer-controlled cam in the rear. This allows the scope to tilt upwards (in the rear) with the front ring as the axis while both rings remain parallel to prevent scope binding. The rear ring tilts to match the front while a cam pushes it up. Ivey also makes tilting +150 MOA Picatinny riser rails.
Ivey offers three scope-mounting products. First is the BR 30-50 (above). This has two, polished 30mm 6061-T6 aluminum rings with bases to fit a 1/2″ x 60 degree Stolle (Davidson) rail on top of an action. Total elevation is +50 MOA. The micrometer adjuster is graduated in true 1 MOA intervals, with 5 MOA of elevation change per rotation. This product costs $385.00 and requires at least 5-1/2″ length mounting base. Available in either “bright” or satin finish.
The newest product is the MSRR-150MOA Riser Rail, a pivoting 5.75″-long Picatinny-style rail that accepts Weaver-style clamping scope rings. This Adjusts from Zero to +150 MOA and raises the scope 1.45″ from the top of the action. The extra height provides clearance for large objectives when the unit is tilted for a full +150 MOA elevation. Cross slots are 5mm wide at 10mm (.394″) spacing. The $425 riser rail is made 6061 T6 Aluminum hard-anodized black. Clamps are heat-treated steel. The micrometer thimble is marked for 1 MOA gradations, and provides 20 MOA per revolution.
The third product, the $445 MSR 30-150, has a pair of 30mm clamping rings that fit on a Picatinny-style (1913 mil-spec) rail. Base cross-slots for two-bolt clamp can accomodate 3/4″ to 1″ slot spacing between centers. Height from top of rail to center of rings = 1.82″ at lowest setting. Note: you need a rail at least 5.625″ long.
The Ivey products are expensive, to be sure, but they are beautifully machined, and they offer unique capabilities for ultra-long-range shooters. With the +150 MOA units you have enough elevation to shoot at 2000+ yards! Even with the +50 unit you can you shoot at 1000 while keeping your scope centered in its elevation travel. We like the idea of using the micrometer to dial within 1 MOA and then just using the scope turrets for fine-tuning. To learn more, visit the Ivey Shooting website, or call Stephen Ivey at (615) 424-8855.
July 5th, 2007
Gene Davis has a new product that boosts the magnification of Leupold, Sightron, and Weaver BR scopes. A threaded ring with a Zeiss lens simply screws on to your scope behind the eyepiece, using the threads provided for lens caps. (Consider it an eyepiece extension). Both 2X and 3X models are available. The 2X version increases image size about 15% while the 3X boosts the viewed image roughly 30%. Hence, on a 36X scope, Davis’ 3X booster creates the equivalent of a 46X power scope. Starting with a 45X Leupold you can get 58X power. Many long-range BR shooters are using this product and reporting to Gene that they can see bullet holes at 600 yards and beyond for the first time. However, there is a price for the extra magnification–the reticle will appear slightly larger, and the image will appear somewhat darker. But, according to Gene: “the image darkening is almost imperceptible during prime daylight hours.” We think Gene’s invention is a winner–a great way to get more magnification at a low cost–$100.00. We also like the fact that, unlike an internal boosting job, you can simply remove the Booster if you want to return to the original magnification level.
Gene reports: “If the scope has screw-in lens caps, these Optical Boosters perform well. We started with a product for the Leupold Competition scopes. We now have Optical Boosters for Weaver T36 and Sightron 36BR as well. We are working on other brands of scopes and the earlier Leupold scopes that do not have threads for the cap. The Optical Boosters do a fantastic job for old or poor eyes. They fit any Leupold scope that has screw-in lens caps, as well as the Weaver and Sightron 36-power target scopes. The Boosters require no internal modification and will not effect the factory warranty. The Optical Boosters (either 2X or 3X) cost $100 delivered.” To purchase, contact Gene Davis at (740) 503-4486 or gdavis10 [at] columbus.rr.com.
Here are reports from two users:
Dick Wright: “Mine is on a 45X Leup…. It’s now a 60X Leup. I got it at the Super Shoot. Excellent optics. You have to re-focus the crosshair. I used it at the Oscoda match where we had lots of mirage. It was a 200 yd. score match and I could see my .22 bullet holes easily. This is totally subjective but, if anything, it made it easier to see. It’s an optical booster that really works for a mere [$100] bucks. All you have to do to reverse the process is un-screw it.”
Joe Pellegrene: “I just got back from the range using my new 3x magnifier on a 45x Leupold. Now it’s a 60x scope and I can’t imagine how I ever lived without it. If anyone’s having trouble seeing their bullet holes on the target this product is well worth the money. It’s easily the most significant piece of equipment that I bought yet.
I plan on using it on several different rifles since you just unscrew it and screw it on the next one. It that takes about 10 seconds to do that. The fine cross hairs on my Leupold were magnified, but so was the target so everything seemed proportional. It’s so much nicer seeing what you’re trying to hit. Now if only Gene would make one for the Nightforce scopes. You can put me down for one Nightforce magnifier. Gene, I wouldn’t mind shooting a 56x Nightforce!”
June 27th, 2007
Forum member Sunbuilder unveiled his new 6-6.5×47 Lapua Improved Varmint rifle today in our Forum. The stock is a beautiful hardwood laminate from Richard Franklin. It’s a rig to envy, with a Stiller Diamondback action, Lilja 30″ 8-twist barrel, and a NightForce 8x32x56 NXS on top. First class components all the way round. Sunbuilder (Scott) has had excellent success already–his two longest groundhog hits were at 778 and 810 yards. Scott writes: “I started hunting with my new rig last week, my first full custom rifle. It was inspired by 6mmBR.com–I’m not sure if I should thank you guys or curse you.” Scott has already seen the potential of his new cartridge: “My improved version of the 6×47 Lapua has a 40° shoulder and reduced body taper. Dave Kiff of PT&G did my reamer design, and he dubbed it the ‘Long Dasher’. The increased velocity potential of this cartridge is partially due to the slightly increased case capacity. The load I am shooting now is 40.5gr N160, Berger 105gr Match BT, .010″ jam, CCI BR4, .002″ neck tension at 3115 fps. This has an ES under 15 fps, and it will group under 2″ at 500 yards if conditions hold. This ‘Long Dasher’ (6-6.5×47) seems to have a lot of potential (and that’s an understatement).”
“I am learning to appreciate how small wind changes at longer ranges can turn a 1″ group into a 4″ one with just a slight shift! I tried several powders (H4350, N160, N560, H4831sc), and primers (CCI 450, BR4, Rem 7 1/2, Fed 205Ms). I got better velocity with H4350, but my barrel likes the N160. I did find a [high-speed] node with H4350.”
A Better Mount for the Spotter and Rangefinder
Scott designed and fabricated a very slick set-up to hold his Zeiss spotting scope and Leica CRF RangeFinder. He’s built a combo bracket that holds both units rock steady, with a parallel line of sight (same axis and elevation). Smart. Very smart. Scott explains: “I built a mount to connect my rangefinder to my spotting scope. The mount can be adjusted, so the spotting scope and rangefinder are both centered on the same object. The only way I have found to get repeatable long-range readings is to make them from a stable base.” Scott, we think you’ve got a winner here with your innovative and clever design. (And we like the idea of a 6-6.5×47 with a 40° shoulder.)
June 21st, 2007
One thing that Jackie Schmidt has been doing over the past few months, is dissassembling Weaver and Sightron 36X Benchrest scopes and locking them up internally. With the internal windage and elevation controls fixed in place, these scope are then mounted using the externally adjustable scope mount system developed by Gene Bukys (shown below).
In working with the different scopes, Jackie has observed that the basic designs of the Weaver T-36 and the Sightron BR scopes are similar. However, Jackie did find some important differences when it comes to boosting scope magnification. The Weaver is a better candidate for boosting because of the way its reticle is installed.
Jackie writes: “I have had both brands apart, and they both share the same design feature in the way the erector tube is mounted, that being a permanently fixed ball and gimble joint sleeve assembly that allows the erector tube to pivot. There is a difference in the way the erector tube sleeve is secured inside the scope body, but that is of no consequence. They both share a similar front objective assembly, (sliding lens assembly cartridge held against a stop by a large coil spring), so there isn’t much advantage of one over the other. I would call it a toss up as to which one might be better, or worse. The Weaver is a couple of ounces lighter. The one difference is if you wanted to boost one or the other. When boosting the power on a scope, one must keep the reticle cross hairs within the focal plain of the eye piece lens assembly. Most scopes are boosted by adding a small lens assembly between the erector tube and the eye piece, moving the reticle assembly back so as to maintain its correct position in relation to the eye piece. Since the Sightron has the reticle mounted in the end of the erector tube, it would be very difficult to move it back. The Weaver is much like the older Leupolds, you can move the reticle assembly back, since it is mounted into the scope body itself.”
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