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June 6th, 2008
The Pentax PF-100ED is one of the best spotting scopes you can buy. It has a huge 100mm front objective, and high-quality ED (low-dispersion) glass for reduced chromatic aberration. The big Pentax accepts all American standard 1.25″ eyepieces, and the Pentax long-eye-relief eyepieces are excellent. The PF-100ED received rave reviews in our Spotting Scope Comparison test a while back, and it’s the scope that tester D. Reever chose for himself.
Right now there’s an “as-new” PF-100ED on eBay, item 120268278337, with a starting price of $899.00 and no reserve. It includes a 20-60X Pentax zoom eyepiece. $899.00 may sound pricey, but this unit, BODY ONLY with NO EYEPIECE, now retails for $1599.00 at leading vendors (Adorama, Amazon, B&H). With zoom eyepiece, new PF-100EDs cost $1800-$1900. If you can grab this Pentax for under $1200.00 it’s a steal. The auction ends in two days.
If you’re looking for big serious spotting scope that can resolve bullet holes at 600 yards and beyond, the Pentax PF-100ED is up to the task. We hope one of our readers snags this unit with a bargain bid.
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June 6th, 2008
 Iowa skies unleashed a deluge recently, so the Iowa 1K BR championship has been moved back two weeks.
Gunsmith and match official Gordy Gritters reports: “I’m Letting everyone know our range is under water and there’s lots more rain in the forecast for this weekend, so we are postponing our June 7th, Iowa 1000-Yard State Championship match two weeks — until July.
We are not going to shoot our State Championship rain date on June 21, but are going to do it on our next regularly scheduled match date- July 12.
In the rush to make this last minute change when we got flooded out, I did not think to check the other nearby club’s schedules until later, and we would have been shooting the same day as Varmint Hunter 600 yard and the Missouri 1000 yard matches that weekend. So we just decided to wait until our regular July match to hold our State Championship match and we’ll make up the missing two matches on September 27. Sorry for any inconvenience!”
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June 5th, 2008
The short videos we have produced for this site have been very popular, and readers have requested more (and better) video offerings. Thanks to Adorama, a large camera and optics retailer, we will be getting a new Canon FS10 video camera. With the new Canon we will be able to shoot higher resolution videos, with better colors, and much improved audio quality.
 The Canon FS10 is part of Canon’s new line-up of Flash-memory video cameras. There are no tapes to fuss with, and you don’t have to worry about internal hard drives or DVD systems. The new Canons record to Flash memory cards so there are no moving parts. This has numerous benefits. Flash-based cameras are less sensitive to shock and vibration and the camera can start recording almost instantly. Importantly, with Flash memory, batteries last much longer since there are no electric motors to run. And the FS10 can record up to 5 hours of video on an 8 Gig SDHC memory card.
After looking at a wide variety of camcorders, we chose the Canon FS10 because it has a number of important features. First, of course, is the Flash memory. Second it has a “microphone in” jack. Using an external microphone will help us reduce background noise when filming interviews or shooting sessions at the range. Third, the camera offers internal image stabilization, and a built-in movie light. Both those features will produce better quality in low light situations. Adorama.com sells the Canon FS10 (item CAFS10) for $419.95, with FREE shipping.
The model FS10 records in standard definition both 4:3 and 16:9 (wide) aspect ratios. We considered Canon’s new High Definition camcorders but these cost twice as much and the AVCHD video files they produce are not yet compatible with most video editing software. Also true High Definition video files are “overkill” for the web — they need to be highly compressed for web use. However, if you’re looking to playback your videos on a High Definition television then Canon’s HD option makes sense. We recommend the Canon VIXIA HF10 for those who want High Definition output. It’s available for $819.95 at Adorama.com.
Adorama has provided a Canon FS10 to AccurateShooter.com in return for promotional considerations.
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June 5th, 2008
Sierra Bullets offers a vast, FREE online library, derived from the 4th and 5th Editions of The Sierra Loading Manual. On Sierra’s ExteriorBallistics.com website, you’ll fine dozens of technical articles, plus useful reference charts for powder burn rates, bullet BCs, and measurement conversions. There’s even a comprehensive Glossary of Shooting Terminology. Overall, ExteriorBallistics.com offers hundreds of pages of great, FREE information.
Tech articles from Sierra’s 5th Ed. Manual that are available online include:
Section 2-2.1 The Ballistic Coefficient Explained
Section 2.3 How the Ballistic Coefficient is Measured
Section 2.3.2 Initial Velocity and Time of Flight Method
Section 2.3.3 Doppler Radar Method
Section 2.4 Lessons Learned from Ballistic Coefficient Testing
Section 3.0 Exterior Ballistic Effects on Bullet Flight
Section 3.1 Effects of Altitude and Atmospheric Conditions
Section 3.2 Effects of Wind
Section 3.3 Effects of Shooting Uphill or Downhill
Section 3.4-3.4.1 Trajectory Considerations for Sighting-In
Section 3.4.2 Determining Zero Range from Firing Test
Section 3.4.3 Sighting in for a Change in Shooting Location
Section 3.5 Point Blank Range
Section 4.2 Yaw of Repose and Resulting Crossrange Deflection
and much, much more….
In addition to the ballistics articles listed above, ExteriorBallistics.com offers a detailed Reloading Section covering equipment and loading methods. Some of the more useful reloading articles include:
Scale and Measures
Case Inspection
Neck- and Full-length Sizing
Bullet Seating.
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June 4th, 2008
In the short-range benchrest game, most of the attention goes to the 10.5-lb Light Varmint Class, and the 13.5-lb Heavy Varmint Class. But there’s another class that is enjoying increased popularity–Hunter Benchrest. In some ways, Hunter BR is more challenging, because you shoot a 10-pounder with a narrower (2.25″ forearm) and a 6-power scope (both LV and HV allow 3″-wide forearms and high-magnification scopes). It takes skilled gun-handling and careful aim to get the most from a Hunter Benchrest rig.
The modern Hunter BR rifle is a far cry from a typical deer rifle, or even a walk-around varminter. Jackie Schmidt explains: “Do not be fooled by that title ‘Hunter Benchrest’, or HBR. The typical HBR Rifle has, like its cousin the Group Rifle, evolved into a very singular-purpose piece of equipment, suited to do one thing very well — namely to shoot Xs in the competitive arena, governed by rather strict sets of rules promulgated by the IBS or the NBRSA.
The two defining factors in HBR are the minimum case capacity, and the 6-power scope. Everything else is just window dressing.
Can one shoot a real factory gun in Hunter BR Class? The answer is yes, IF your factory rifle meets these qualifications:
■ Total gun weight no more than 10 pounds.
■ Stock forearm must be convex (at least slightly) on the bottom, and no more than 2.25″ wide.
■ Gun must have magazine capable of holding at least two cartridges. (Normally, however, Hunter BR shooters don’t feed from the magazine.)
■ Gun must shoot a cartridge with at least 45 grains of water capacity (the equivalent of a 30-30).
■ Scope must be a 6-power or capable of being set and used at 6X magnification.
If you go to the IBS website, you will see that there are a couple of exceptions, but in the end, to compete for the prize, you must have a legal Hunter BR rifle. But even if you’re not completely within the rules, most match directors will let a newcomer shoot along, for the fun of it, and to see what the game is really all about.”
Top Hunter BR shooter Al Nyhus tells us: “As Jackie has pointed out, the Hunter class in Benchrest has mutated into full race BR rigs…much like NASCAR ‘stock cars’ or NHRA ‘Pro Stock’. The original intent of Hunter was for a class where the average person with an interest in accuracy could bring a good shooting hunting rifle and give BR a try. Still a darn good idea, to me.
Here’s a photo of my Hunter Benchrest rig, which is pretty typical of what’s being used at this point in time. My Hunter BR rig is pretty standard stuff except for the chambering. It features a Stolle R/L Kodiak action tweaked a bit by Stan Ware, Kostyshyn 1:17 four groove, chambered for the 30 WolfPup (30BR .240″ long/.085″ neck length). The photo below shows a Leupold 6X scope but I’ve been using a Sightron 6X lately.
This stock is an old Speedy/McMillan pattern HBR stock. I had it dipped (externally coated) with a carbon fiber pattern. By the rules, Hunter rifles cannot be glue-ins, so pillar bedding is the norm. I guess the forearm is about as ‘convex’ on the bottom as any other stock currently in use. This is another area where the guns have evolved and the rulebook(s) haven’t exactly kept pace with the current state of what’s being used.”
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June 3rd, 2008
Most serious shooters can tell you the muzzle velocity (MV) of their ammunition, based on measurements taken with a chronograph, or listed from a manufacturer’s data sheet. (Of course, actual speed tests conducted with YOUR gun will be more reliable.)
Bullet RPM = MV X 720/Twist Rate (in inches)
Photo by Werner Mehl, www.kurzzeit.com, all rights reserved.
However, if you ask a typical reloader for the rotational rate of his bullet, in revolutions per minute (RPM), chances are he can’t give you an answer. Knowing the true spin rate or RPM of your bullets is very important. First, spin rate, or RPM, will dramatically affect the performance of a bullet on a game animal. Ask any varminter and he’ll tell you that ultra-high RPM produces more dramatic hits with more “varmint hang time”. Second, RPM is important for bullet integrity. If you spin your bullets too fast, this heats up the jackets and also increases the centrifugal force acting on the jacket, pulling it outward. The combination of heat, friction, and centrifugal force can cause jacket failure and bullet “blow-ups” if you spin your bullets too fast.
Accuracy and RPM
Additionally, bullet RPM is very important for accuracy. Nearly all modern rifles use spin-stablized bullets. The barrel’s rifling imparts spin to the bullet as it passes through the bore. This rotation stablizes the bullet in flight. Different bullets need different spin rates to perform optimally. Generally speaking, among bullets of the same caliber, longer bullets need more RPM to stabilize than do shorter bullets–often a lot more RPM.
It is generally believed that, for match bullets, best accuracy is achieved at the minimal spin rates that will fully stabilize the particular bullet at the distances where the bullet must perform. That’s why short-range 6PPC benchrest shooters use relatively slow twist rates, such as 1:14″, to stabilize their short, flatbase bullets. They could use “fast” twist rates such as 1:8″, but this delivers more bullet RPM than necessary. Match results have demonstrated conclusively that the slower twist rates produce better accuracy with these bullets.
Calculating Bullet RPM from MV and Twist Rate
The lesson here is that you want to use the optimal RPM for each bullet type. So how do you calculate that? Bullet RPM is a function of two factors, barrel twist rate and velocity through the bore. With a given rifling twist rate, the quicker the bullet passes through the rifling, the faster it will be spinning when it leaves the muzzle. To a certain extent, then, if you speed up the bullet, you can use a slower twist rate, and still end up with enough RPM to stabilize the bullet. But you have to know how to calculate RPM so you can maintain sufficient revs.
Bullet RPM Formula
Here is a simple formula for calculating bullet RPM:
MV x (12/twist rate in inches) x 60 = Bullet RPM
Quick Version: MV X 720/Twist Rate = RPM
Example One: In a 1:12″ twist barrel the bullet will make one complete revolution for every 12″ (or 1 foot) it travels through the bore. This makes the RPM calculation very easy. With a velocity of 3000 feet per second (FPS), in a 1:12″ twist barrel, the bullet will spin 3000 revolutions per SECOND (because it is traveling exactly one foot, and thereby making one complete revolution, in 1/3000 of a second). To convert to RPM, simply multiply by 60 since there are 60 seconds in a minute. Thus, at 3000 FPS, a bullet will be spinning at 3000 x 60, or 180,000 RPM, when it leaves the barrel.
Example Two: What about a faster twist rate, say a 1:8″ twist? We know the bullet will be spinning faster than in Example One, but how much faster? Using the formula, this is simple to calculate. Assuming the same MV of 3000 FPS, the bullet makes 12/8 or 1.5 revolutions for each 12″ or one foot it travels in the bore. Accordingly, the RPM is 3000 x (12/8) x 60, or 270,000 RPM.
 Implications for Gun Builders and Reloaders
Calculating the RPM based on twist rate and MV gives us some very important information. Number one, we can tailor the load to decrease velocity just enough to avoid jacket failure and bullet blow-up at excessive RPMs. Number two, knowing how to find bullet RPM helps us compare barrels of different twist rates. Once we find that a bullet is stable at a given RPM, that gives us a “target” to meet or exceed in other barrels with a different twist rate. Although there are other important factors to consider, if you speed up the bullet (i.e. increase MV), you MAY be able to run a slower twist-rate barrel, so long as you maintain the requisite RPM for stabilization and other factors contributing to Gyroscopic Stability are present. In fact, you may need somewhat MORE RPM as you increase velocity, because more speed puts more pressure, a destabilizing force, on the nose of the bullet. You need to compensate for that destabilizing force with somewhat more RPM. But, as a general rule, if you increase velocity you CAN decrease twist rate. What’s the benefit? The slower twist-rate barrel may, potentially, be more accurate. And barrel heat and friction may be reduced somewhat.
Just remember that as you reduce twist rate you need to increase velocity, and you may need somewhat MORE RPM than before. (As velocities climb, destabilizing forces increase somewhat, RPM being equal.) There is a formula by Don Miller that can help you calculate how much you can slow down the twist rate as you increase velocity.
CLICK HERE for Miller Formula in Excel Spreadsheet Format
That said, we note that bullet-makers provide a recommended twist rate for their bullets. This is the “safe bet” to achieve stabilization with that bullet, and it may also indicate the twist rate at which the bullet shoots best. Though the RPM number alone does not assure gyroscopic stability, an RPM-based calculation can be very useful. We’ve seen real world examples where a bullet that needs an 8-twist barrel at 2800 FPS MV, would stabilize in a 9-twist barrel at 3200 FPS MV. Consider these examples.
MV = 2800 FPS
8-Twist RPM = 2800 x (12/8) x 60 = 252,000 RPM
MV = 3200 FPS
9-Twist RPM = 3200 x (12/9) x 60 = 256,000 RPM
Of course max velocity will be limited by case capacity and pressure. You can’t switch to a slower twist-rate barrel and maintain RPM if you’ve already maxed out your MV. But the Miller Formula can help you select an optimal twist rate if you’re thinking of running the same bullet in a larger case with more potential velocity.
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June 3rd, 2008
Hornady provides a good, basic Guide to External Ballistics, covering the key principles of small arms ballistics. This is a good starting point to learn how bullet shape, wind, and velocity determine how bullets perform in flight.
If you’ve ever wondered about the meaning of Ballistics Coefficient, or wondered how different zeros affect bullet trajectories, this article will explain the basics that you need to know. Here’s an example:
Ballistic Coefficient Definition
“A ballistic coefficient is the measure of a bullet’s relative ability to overcome air resistance. Each bullet can be assigned a numerical value expressing this efficiency. The basis of this value is a ratio comparing the performance characteristics of a particular bullet against the known trajectory characteristics of a standard projectile. The ratio compares the drag of a bullet (loss of velocity caused by air resistance encountered in flight) to the drag of the standard projectile. Expressed as a formula:
The standard projectile on which all Hornady Bullets were compared was the G1 Model, based on work begun in France and refined at the U. S. Army Ballistic Research Laboratories, Aberdeen Proving Ground, Maryland. Ballistic coefficients for all Hornady Bullets were determined by computer calculations using data from test firing research performed in our 200 yard underground test range.”
Hornady also offers a free, interactive Ballistics calculator on its web site. While not as detailed or sophisticated as the JBM web ballistics calculator, the Hornady Ballistics Calculator is clean, simple, and easy to use. This will generate bullet drop in minutes of angle (MOA) at distances out to 1000 yards, along with wind drift in MOA and inches. The Hornady ballistics calculator also allow you to pre-select for handgun, short-range rifle, match (High Power) rifle, and long-range rifle. This simplifies the data presented, giving you just the ranges you need.
CLICK HERE for Hornady Ballistics Calculator
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June 2nd, 2008
Mac Tilton Operates MT Guns, with shops in Southern California and Nevada. MT Guns has one of the most extensive collections of pre-owned target rifles (primarily rimfire), in the world. Mac has been in the firearms business some 55 years, having obtained his first FFL as a teen-ager. In recent years, using the services of expert buying agents in Europe, MT Guns has acquired a huge inventory of premium target guns including hundreds of Anschütz match rifles.
In addition to the Anschütz line, MT Guns has a very large selection of the classic BSA Martinis, including dozens of the desireable MK III match guns. Mac also has a large collection of Walthers, Suhls, Tikkas, Vostoks, Weihrauchs and many other “exotics” from Europe. Being a left-hander himself, Mac maintains an extensive selection of left-handed rifles.
CLICK HERE to WATCH VIDEO about BSA Martini Rifles.
In addition to complete rifles, MT Guns has a large inventory of barrels and a wide selection of “iron” target sights, including rare 19th-century Creedmoor sights. For a fan of precision rimfires and “golden age” rifles, visiting MT Guns shop in Santa Barbara is like striking the mother load. This editor spent four hours with Mac recently and we only saw a small fraction of the inventory.
CLICK HERE for Anschütz and Walther Collection VIDEO.
In addition to selling used target rifles, MT Guns is the USA importer for Barnard Actions. Mac is also a skilled gunsmith and he can build complete rifles on a Barnard or the action of your choice. Mac has built many High Power rifles based on the relatively inexpensive but high-quality Tikka 595 action, often fitted with a Barnard trigger.
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June 2nd, 2008
 MidSouth Shooters Supply has a new Product Blog that showcases new items and special bargains of the day. One or more featured items are added every day.
We applaud Midsouth for adopting the Blog format to highlight new products and special sale items. This makes it easy for the consumer to check for hot deals with a single click, and Midsouth provides nice, large photos and full descriptions of sale items.
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June 1st, 2008
 Brownell’s offers over 50 free instructional videos on its website. From the index page, just click the appropriate link and your video of choice will stream in your browser. Alternatively, you can download the videos to your computer hard-drive for later playback.
All videos are narrated by one of Brownell’s gunsmiths or technicians. Complex tasks may be covered in multiple videos. Listed below are some of the recommended videos:
AR15 Bolt Disassembly/Cleaning
How to Fix Light Rust on a Gun
Mounting Rifle Scopes
Measuring Rifle Sight Heights
Remington 700 ADL to BDL Conversion Kits
Prepping Your Firearm For Winter Storage
Prepping a Rifle For Cold-Weather Hunting
Installing 10/22 Barrels
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June 1st, 2008
Eric Stecker of Berger Bullets notified us that Berger wants to hire a technical services representative. The candidate must be an experienced rifle reloader who can work on the phone 4-6 hours daily, Monday through Friday. Since the job can be done remotely (at your location), you can pretty much work anywhere in the USA.
Stecker reports: “Berger is growing. Daily we receive requests for technical assistance. We are looking to hire a part time (remote) technical representative. Requirements for this position are more than five years experience as a rifle case reloader. You must be well-versed in reloading for rifle cartridges in calibers for which we make bullets (17 cal through 30 cal for now, soon to include 338 through 50 cal).
 You must be able to provide focused attention to those who need assistance. The job requires 4 to 6 hours, each day, Monday through Friday (excluding holidays and vacation). You must be computer literate and comfortable on the phone.
Salary + Free Bullets
It is not a requirement, but being an active, competitive shooter is a plus. This is a part time position which does not include medical benefits. However you’ll receive as many Berger Bullets as you can shoot, along with your pay (to be set based on experience).
It is my sincere hope that this opportunity finds someone who is filled with a genuine love of the shooting sports and who has some time on their hands. Those who are genuinely interested (and available) need to send their resume (shooting and reloading experience focused) to me at eric.stecker [at] bergerbullets.com.”
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