July 31st, 2014
Burris Optics is currently offering significant rebates on three lines of scopes. You can get up to $100.00 in rebates on Burris Tactical and Fullfield II scopes. For the innovative Eliminator optics with built-in laser rangefinders, the savings are even bigger — you can get up to $200.00 in rebates with your purchase. We like the Eliminator scopes for Varmint hunting. The built-in rangefinder instantly calculates the needed hold-over, based on the target distance. Then the scope displays the corrected aim point as a red dot on the vertical cross-hair. Just put the red dot on your target and pull the trigger. The Eliminator does all the work for you — no turret clicking needed.
CLICK HERE for Burris REBATE Details and Forms
These Burris products are available now at Grafs.com. Rebates available for purchases made between July 1, 2014 and December 31, 2014. Mail-in form must be signed, dated, and post-marked by January 31, 2015. View Full Offer Details.
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July 29th, 2014
Nightforce now offers a 5-20x56mm SHV scope that retails for $1170.00 (non-illuminated) or $1299.00 (illuminated). This follows up on Nightforce’s successful 4-16x56mm SHV scope. The higher magnification range suits long range hunters and the large 56mm objective provides excellent low-light hunting capability. The 5-20 SHV offers plenty of travel: 80 MOA total elevation, 50 MOA windage.
The 5-20x56mm SHV boasts capped, waterproof turrets with 1/4-MOA click values, and 10 MOA per revolution on the elevation turret. The scope offers a side parallax control (25 yards to infinity), plus a European-style, fast-focus eyepiece.
Two reticles are offered for the 5-20x56mm SHV. The IHR features large dagger-style pointers, an open field at the top, and an cross in the center. The MOAR reticle has 1 MOA elevation and windage markings, with a floating center crosshair. With either reticle, illumination is optional at extra cost.
Product Tip from EdLongrange. We welcome reader submissions.
Our friend Len Backus of LongRangeHunting.com has checked out the new 5-20x56mm Nightforce and he is impressed: “With a 56mm objective the SHV’s light transmission is outstanding even at high power. Nightforce has added a ‘Zero Set’ feature which is a set-screw based stop system allowing you to dial back to your pre-set zero and stopping you from dialing past. It’s not quite as sharp a stop as their ‘Zero Stop’ but it will definitely do the trick. I bought my first Nightforce scope about 14 years ago. In summer of 2012 I had a four-hour private tour of the Nightforce headquarters. I remember being so impressed with the forward thinking going on there. It was obvious they were preparing for a major push on new technology and new products and this SHV is an absolute winner in that regard.”
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July 10th, 2014
Weaver has a brand new, high-magnification, 46X target scope. Chances are you haven’t heard a thing about it — the new Weaver T-Series XR 46x48mm scope is so new you won’t even find it on the Weaver website. Compared to the older T-36, this new 46-power scope offers more magnification, more elevation, a larger front objective (48mm vs. 40mm), and a larger 30mm main tube (compared to 1″ for the old T-36). The new XR 46X Weaver also features side-focus parallax control. That’s a big change. You could instantly spot a classic Weaver T-36 by the adjustable front objective with its knurled ring and yardage markings. The T-Series XR 46X (as well as the new XR 24X and XR 36X) have the parallax control on the left side of the main tube (photo below).
We have looked through the new Weaver 46X scope and it is very sharp. Brightness is good — it seems comparable with a Leupold 45x45mm Competition (but that was on a bright, sunny day). Initial tests show the clicks to be tactile and positive, but we haven’t had a chance to do a full “box test” to confirm tracking. Weaver claims the new XR series scopes will focus down to 50 feet, but with the 46X we had some questions about its extreme close-focus capability. If you’re shooting beyond 50 yards, the focus should be fine.
The new T-Series 46X XR is offered with two reticle choices, a fine cross-hair (FCH), or FCH with 1/16th MOA dot. Both reticles are well-suited for benchrest work. The current “street price” for the new 46X Weaver is $829.95. That’s way more than the old T-36, but it undercuts Leupold fixed-power competition scopes by hundreds of dollars. We know of only two vendors who currently carry the Weaver 46X. These are Killough Shooting Sports, and Bruno Shooters Supply.
New 24X and 36X T-Series XR Scopes with Side-Focus and 1″ Tubes
The new 46-power XR scope is the star of the XR line-up. Designed to go head-to-head with Leupold’s 45X Competition scope, the 46X Weaver XR offers a modern 30mm main-tube and large (48mm) front objective. If you don’t need the bigger tube and larger objective, but still want side-focus parallax control, Weaver offers two other new XR scopes — a 36x40mm and a 24x40mm. These will both retail for under $600.
Dan Killough offers the black-finish 36-power XR for $559.95 and the black-finish 24-power XR for $549.95. Silver models are slightly more. These 1″-tube XR scopes are worth considering, but keep in mind that you can now purchase the older T-series scopes with adjustable front objectives for well under $400.00. For benchrest shooting at a fixed distance, side-focus is not necessary; adjustable front objectives work just fine. Just set and forget.
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July 9th, 2014
Using a spotting scope seems simple. Just point it at the target and focus, right? Well, actually, it’s not that simple. Sometimes you want to watch mirage or trace, and that involves different focus and viewing priorities. Along with resolving bullet holes (or seeing other features on the target itself), you can use your spotting scope to monitor mirage. When watching mirage, you actually want to focus the spotting scope not on the target, but, typically, about two-thirds of the distance downrange. When spotting for another shooter, you can also use the spotting scope to watch the bullet trace, i.e. the vapor trail of the bullet. This will help you determine where the bullet is actually landing, even if it does not impact on the target backer.
In this video, SFC L.D. Lewis explains how to use a spotting scope to monitor mirage, and to watch trace. SFC Lewis is a former Army Marksmanship Unit member, U.S. Army Sniper School instructor, and current U.S. Army Reserve Service Rifle Shooting Team member. In discussing how precision shooters can employ spotting scopes, Lewis compares the use of a spotting scope for competition shooters vs. military snipers. NOTE: You may wish to turn up the audio volume, during the actual interview segment of this video.
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July 7th, 2014
Are you looking for an ultra-reliable, high-magnification target scope at a budget price? Well, you’re in luck. Right now, Bruno Shooters Supply has Weaver T-36 target series scopes on sale for just $379.95. That’s a great deal in today’s marketplace. These are non-zoom, fixed-power scopes suitable for benchrest competition. Weaver T-series scopes are well-known for their durability and repeatability. They also offer 1/8 minute of angle clicks for both windage and elevation. This is desirable when you’re trying to shoot bughole groups. Understand that, with a 40mm objective, a Weaver T-36 scope is NOT as bright as a Nightforce or March Competition scope. However, the Weaver is a fraction of the cost of those elite brands. Despite its affordable price, the Weaver T-36 has won plenty of benchrest matches.
Weaver T-Series scopes feature an adjustable objective for parallax-free shooting without moving the point of impact. Weaver T-36 features include 1/8 MOA windage and elevation adjustments using Weaver’s Micro-Trac dual-spring, two bearing contact design that allows for more independent movement in windage and elevation, and fully multi-coated lenses. T-36 scopes are waterproof, fogproof, shockproof, and covered by a limited lifetime warranty.
Other Vendors Are Charging Much More for Weaver T-Series 36X Scopes
Yes, the $379.95 price at Bruno Shooters Supply is a very good deal. Here is a screen shot of comparative prices charged by other vendors, as of today, July 7, 2014. See for yourself:
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June 29th, 2014
Riflescopes are mechanical contraptions. One of the sad realities about precision shooting is that, sooner or later, you will experience a scope failure. If you’re lucky it won’t happen in the middle of a National-level competition. And hopefully the failure will be dramatic and unmistakable so you won’t spend months trying to isolate the issue. Unfortunately, scope problems can be erratic or hard to diagnose. You may find yourself with unexplained flyers or a slight degradation of accuracy and you won’t know how to diagnose the problem. And when a 1/8th-MOA-click scope starts failing, it may be hard to recognize the fault immediately, because the POI change may be slight.
When An Expensive Scope Goes Bad
Recently, this editor had a major-brand 8-25x50mm scope go bad. How did I know I had a problem? Well the first sign was a wild “drop-down” flyer at a 600-yard match. After shooting a two-target relay, I took a look at my targets. My first 5-shot group had five shots, fairly well centered, in about 2.2″. Pretty good. Everything was operating fine. Then I looked at the second target. My eye was drawn to four shots, all centered in the 10 Ring, measuring about 2.4″. But then I saw the fifth shot. It was a good 18″ low, straight down from the X. And I really mean straight down — if you drew a plumb line down from the center of the X, it would pass almost through the fifth shot.
That was disconcerting, but since I had never had any trouble with this scope before, I assumed it was a load problem (too little powder?), or simple driver error (maybe I flinched or yanked the trigger?). Accordingly, I didn’t do anything about the scope, figuring the problem was me or the load.
But, at the next range session, things went downhill fast. In three shots, I did manage to get on steel at 600, with my normal come-up for that distance. Everything seemed fine. So then I switched to paper. We had a buddy in the pits with a walkie-talkie and he radioed that he couldn’t see any bullet holes in the paper after five shots. My spotter said he thought the bullets were impacting in the dirt, just below the paper. OK, I thought, we’ll add 3 MOA up (12 clicks), and that should raise POI 18″ and I should be on paper, near center. That didn’t work — now the bullets were impacting in the berm ABOVE the target frame. The POI had changed over 48″ (8 MOA). (And no I didn’t click too far — I clicked slowly, counting each click out loud as I adjusted the elevation.) OK, to compensate now I took off 8 clicks which should be 2 MOA or 12″. No joy. The POI dropped about 24″ (4 MOA) and the POI also moved moved 18″ right, to the edge of the target.
For the next 20 shots, we kept “chasing center” trying to get the gun zeroed at 600 yards. We never did. After burning a lot of ammo, we gave up. Before stowing the gun for the trip home, I dialed back to my 100-yard zero, which is my normal practice (it’s 47 clicks down from 600-yard zero). I immediately noticed that the “feel” of the elevation knob didn’t seem right. Even though I was pretty much in the center of my elevation (I have a +20 MOA scope mount), the clicks felt really tight — as they do when you’re at the very limit of travel. There was a lot of resistance in the clicks and they didn’t seem to move the right amount. And it seemed that I’d have four or five clicks that were “bunched up” with a lot of resistance, and then the next click would have almost no resistance and seem to jump. It’s hard to describe, but it was like winding a spring that erratically moved from tight to very loose.
At this point I announced to my shooting buddies: “I think the scope has taken a dump.” I let one buddy work the elevation knob a bit. “That feels weird,” he said: “the clicks aren’t consistent… first it doesn’t want to move, then the clicks jump too easily.”
Convinced that I had a real problem, the scope was packed up and shipped to the manufacturer. So, was I hallucinating? Was my problem really just driver error? I’ve heard plenty of stories about guys who sent scopes in for repair, only to receive their optics back with a terse note saying: “Scope passed inspection and function test 100%. No repairs needed”. So, was my scope really FUBAR? You bet it was. When the scope came back from the factory, the Repair Record stated that nearly all the internal mechanicals had been replaced or fixed: “Replaced Adjustment Elevation; Replaced Adjustment Windage; Reworked Erector System; Reworked Selector; Reworked Parallax Control.”
How to Diagnose Scope Problems
When you see your groups open up, there’s a very good chance this is due to poor wind-reading, or other “driver error”. But my experience showed me that sometimes scopes do go bad. When your accuracy degrades without any other reasonable explanation, the cause of the problem may well be your optics. Here are some of the “symptoms” of scope troubles:
1. Large shot-to-shot variance in Point of Impact with known accurate loads.
2. Uneven tracking (either vertical or horizontal).
3. Change of Point of Impact does not correspond to click inputs.
4. Inability to zero in reasonable number of shots.
5. Unexpected changes in needed click values (compared to previous come-ups).
6. Visible shift in reticle from center of view.
7. Changed “feel” or resistance when clicking; or uneven click-to-click “feel”.
8. Inability to set parallax to achieve sharpness.
9. Turrets or other controls feel wobbly or loose.
10. Internal scope components rattle when gun is moved.
Source of Problem Unknown, but I Have a Theory
Although my scope came with a slightly canted reticle from the factory, it had otherwise functioned without a hitch for many years. I was able to go back and forth between 100-yard zero and 600-yard zero with perfect repeatability for over five years. I had confidence in that scope. Why did it fail when it did? My theory is side-loading on the turrets. I used to carry the gun in a thick soft case. I recently switched to an aluminum-sided hard case that has pretty dense egg-crate foam inside. I noticed it took some effort to close the case, though it was more than big enough, width-wise, to hold the gun. My thinking is that the foam wasn’t compressing enough, resulting in a side-load on the windage turret when the case was clamped shut. This is just my best guess; it may not be the real source of the problem. Remember, as I explained in the beginning of this story, sometimes scopes — just like any mechanical system — simply stop working for no apparent reason.
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June 29th, 2014
If you need a scope for your AR-platform rifle, Nikon has you covered. With Nikon’s latest AR New Rules promotion, you can save up to $100.00 on caliber-specific AR riflescopes and mounts.
The New Rules for AR promotion offers shooters up to $100 instant savings on a wide selection of AR-dedicated riflescopes. The New Rules for AR promotion includes nearly 20 models of AR-dedicated riflescopes, including the M-308, M-223, and P-300 BLK lines. This Nikon promotion is in effect right now, and will run through August 2, 2014. To learn more about the New Rules for AR promotion, visit www.nikonpromo.com.
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June 26th, 2014
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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June 10th, 2014
Father’s Day (Sunday, June 15) is right around the corner. If dad enjoys hunting, here’s a way to save fifty bucks on a nice gift for the old man. Now through June 15, 2014, Zeiss is offering a $50.00 rebate on the TERRA 3X series rifle-scopes or TERRA ED Binoculars. The scopes offer 1/4-MOA clicks with a choice of standard Z-Plex or RZ6 or RZ8 ballistic reticles. Pick your power: 2-7x32mm, 3-9x42mm, 4-12x42mm, 3-9x50mm, and 4-12x50mm. CLICK Here for more details.
If you’re wondering about these binoculars, trust us, they are high quality. TERRA ED Binoculars feature SCHOTT ED glass — just about the best you can get. These binocs, in 8x42mm or 10x42mm versions, offer great low-light performance and a wide-angle field of view.
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May 28th, 2014
While attending the CA Long Range Championship a while back, we had the opportunity to test the performance of a high-magnification (63X) spotting scope in near-ideal conditions (maybe the best I’ve ever witnessed). On the event’s last day we arrived at 5:45 am, literally as the sun was cresting the horizon. I quickly deployed our Pentax PF-100ED spotting scope, fitted with a Pentax SMC-XW 10mm fixed-power eyepiece. When used with the 100mm Pentax scope, this 10mm eyepiece yields 63X magnification. Befitting its $359.00 price, this eyepiece is extremely clear and sharp.
At the crack of dawn, viewing conditions were ideal. No mist, no mirage, no wind. The first thing this Editor noticed was that I could see metal nail heads on the target boards. That was astonishing. As soon as the first practice targets went up, to my surprise, I could see 6.5mm, 7mm, and 30-caliber bullet holes in the white at 1000 yards.
That’s right, I could see bullet holes at 1000. I know many of you folks may not believe that, but there was no mistaking when I saw a 7mm bullet cut the white line separating the Nine Ring and Eight Ring on the target in view. (I was watching that target as the shot was fired and saw the shot-hole form). And when I looked at the 30-cal targets, the bullet holes in the white were quite visible. In these perfect conditions I could also make out 3/8″ bolt heads on the target frames.
The Human Factor
When viewing the bullet holes, I was using my left naked eye (no safety glasses or magnification). I also had a contact lens in my right eye (needed for distance vision). To my surprise, while I could see the bullet holes without much difficulty with my left eye, things were fuzzier and slightly more blurry with the right eye, even when I re-focused the scope.
Then I invited 3 or 4 shooters to look through the scope. One younger guy, with good eyes, said immediately: “Yeah, I can see the holes — right there at 4 o’clock and seven o’clock. Wow.” Some older guys, who were wearing glasses, could not see the holes at all, no matter what we did to the scope’s main focus and diopter adjustment.
The lesson here — if you have to wear glasses or corrective contact lenses, just that extra bit of optical interference may make a difference in what you can see through the scope. Basically anything that goes between the scope eyepiece and your eyeball can degrade the image somewhat. So… you may be better off removing your glasses if you can still obtain good focus sharpness using the diopter adjustment and focus ring. I did the left vs. right eye test a half dozen times, and I could definitely see small features at 1000 yards with my naked eye that I could not see with my right eye fitted with a contact lens. (I did have to re-focus the scope for each eye, since one had a corrective lens while the other did not.)
Mirage Degrades Image Sharpness and Resolution
The “magic light” prevailed for only an hour or so, and then we started to get some mirage. As soon as the mirage appeared I was no longer able to see raw bullet holes, though I could still easily see black pasters on the black bulls. When the mirage started, the sharpness of the visible image degraded a huge amount. Where I could see bullet holes at dawn, by mid-morning I could barely read the numbers on the scoring rings. Lesson: If you want to test the ulimate resolution of your optics, you need perfect conditions.
Chromatic Aberration Revealed
As the light got brighter and the mirage increased I started to see blue and red fringing at the edges of the spotting disk and the large numerals. This was quite noticeable. On one side of the bright, white spotting disc you could see a dark red edge, while on the other side there was a blue edge (harder to see but still present).
The photo below was taken through the Pentax spotter lens using a point and shoot camera held up to the eyepiece. The sharpness of the Pentax was actually much better than this photo shows, but the through-the-lens image does clearly reveal the red and blue fringing. This fringing is caused by chromatic aberration — the failure of a lens to focus all colors to the same point. Chromatic aberration, most visible at high magnification, causes different wavelengths of light to have differing focal lengths (see diagram). Chromatic aberration manifests itself as “fringes” of color along boundaries that separate dark and bright parts of the image, because each color in the optical spectrum cannot be focused at a single common point on the optical axis. Keep in mind that the Pentax does have “ED” or low-dispersion glass, so the effect would be even more dramatic with a cheaper spotting scope.
If you wonder why top-of-the-line spotting scopes (such as the $3900 Leica APO-Televid 82) cost so much, the answer is that they will deliver even LESS chromatic aberration at long range and high magnification. With their exotic apochromatic (APO), ultra-low-dispersion glass, a few ultra-high-end spotting scopes can deliver an image without the color edging you see in the photo above.
The Pentax PF-100ED is a heck of a spotting scope. Any scope that can resolve bullet holes at 1000 yards is impressive. But if you want the ultimate in optical performance, with minimal chromatic aberration, you may need to step up to something like the 88mm Kowa Prominar TSN-883 with Flourite Crystal lenses ($2450.00 body only), or the 82mm Leica APO ($3899.00 with 25-50X eyepiece).
EDITOR’s NOTE: The purpose of this report is to show what is possible… in IDEAL conditions. With this Pentax 100mm, as well as a Swarovski 80mm, we have often been able to resolve 6mm bullet holes at 600 yards. But again, that performance requires really good viewing conditions. By 10:00 am at my range, even with the 100mm Pentax at 75 power, seeing 6mm bullet holes is “iffy” at best. So don’t go out and mortgage the house to buy a $4000 optic with the hope that you’ll be able to spot your shots at 1000 yards. If conditions are anything less than perfect, you’ll be lucky to see bullet holes at 500 yards. The real solution for very long-range spotting is to set up a remote target cam that broadcasts a video picture to a screen at your shooting station.
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May 22nd, 2014
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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May 21st, 2014
There is nothing more frustrating (or embarassing) than sending a live round into your expensive new chronograph. As the photo below demonstrates, with most types of chronographs (other than the barrel-hung Magnetospeed), you can fatally injure your expensive chrono if it is not positioned precisely.
When setting up a chrono, we always unload the rifle, remove the bolt and bore-sight to ensure that the path of the bullet is not too low. When bore-sighting visually, set up the rifle securely on the sandbags and look through the bore, breech to muzzle, lining up the barrel with your aim point on the target. Then (during an appropriate cease-fire), walk behind the chronograph. Looking straight back through the “V” formed by the sky-screens, you should be able to see light at the end of the barrel if the gun is positioned correctly. You can also use an in-chamber, laser bore-sighter to confirm the visual boresighting (see photo).
Adjust the height, angle and horizontal position of the chronograph so the bullet will pass through the middle of the “V” below the plastic diffusers, no less than 5″ above the light sensors. We put tape on the front sky-screen supports to make it easier to determine the right height over the light sensors.
Use a Test Backer to Confirm Your Bullet Trajectory
You can put tape on the support rods about 6″ up from the unit. This helps you judge the correct vertical height when setting up your rifle on the bags. Another trick is to hang a sheet of paper from the rear skyscreen and then use a laser boresighter to shine a dot on the paper (with the gun planted steady front and rear). This should give you a good idea (within an inch or so) of the bullet’s actual flight path through the “V” over the light sensors. Of course, when using a laser, never look directly at the laser! Instead shine the laser away from you and see where it appears on the paper.
Alignment of Chronograph Housing
Make sure the chrono housing is parallel to the path of the bullet. Don’t worry if the unit is not parallel to the ground surface. What you want is the bullet to pass over both front and rear sensors at the same height. Don’t try to set the chrono height in reference to the lens of your scope–as it sits 1″ to 2″ above your bore axis. To avoid muzzle blast interference, set your chronograph at least 10 feet from the end of the muzzle (or the distance recommended by the manufacturer).
Rifles with Elevated Iron Sights
All too often rookie AR15 shooters forget that AR sights are positioned roughly 2.4″ above the bore axis (at the top of the front sight blade). If you set your bullet pass-through point using your AR’s front sight, the bullet will actually be traveling 2.4″ lower as it goes through the chrono. That’s why we recommend bore-sighting and setting the bullet travel point about 5-8″ above the base of the sky-screen support shafts. (Or the vertical distance the chronograph maker otherwise recommends). NOTE: You can make the same mistake on a scoped rifle if the scope is set on very tall rings, so the center of the cross-hairs is much higher than the bore axis line.
TARGET AIM POINT: When doing chrono work, we suggest you shoot at a single aiming point no more than 2″ in diameter (on your target paper). Use that aiming point when aligning your chrono with your rifle’s bore. If you use a 2″ bright orange dot, you should be able to see that through the bore at 100 yards. Using a single 2″ target reduces the chance of a screen hit as you shift points of aim. If you shoot at multiple target dots, place them in a vertical line, and bore sight on the lowest dot. Always set your chron height to set safe clearance for the LOWEST target dot, and then work upwards only.
Other Chronograph Tips from Forum Members:
When using a chronograph, I put a strip of masking tape across the far end of the skyscreens about two-thirds of the way up. This gives me a good aiming or bore-sighting reference that’s well away from the pricey bits. I learned that one the hard way. — German Salazar
A very easy and simple tool to help you set up the chronograph is a simple piece of string! Set your gun (unloaded of course) on the rest and sight your target. Tie one end of the string to the rear scope ring or mount, then pull the string along the barrel to simulate the bullet path. With the string showing the bullet’s path, you can then easily set the chronograph’s placement left/right, and up/down. This will also let you set the chrono’s tilt angle and orientation so the sensors are correctly aligned with the bullet path. — Wayne Shaw
If shooting over a chrono from the prone position off a bipod or similar, beware of the muzzle sinking as recoil causes the front of the rifle to drop. I “killed” my first chronograph shooting off a gravel covered firing point where I’d not given enough clearance to start with and an inch or two drop in the muzzle caused a bullet to clip the housing. — Laurie Holland
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