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April 25th, 2009
 Ever wondered what twist rate is required to stabilize a particular bullet? Or would you like to see how changes in spin rates (rpm) affect bullet stability? Well thanks to our friends from Canada, you’ll find helpful formulas online that answer many questions about external ballistics.
The Ballistics Page for the Canadian National Firearms Association (NFA) website offers a variety of useful programs and data charts created by Peter Cronhelm. These include:
Caliber Twist Rate Chart
Greenhill Formula Twist Calculator
Bullet Stability Calculator (requires MS Excel)
Ballistic Coefficients Chart (MS Word), (Or DOWNLOAD HERE.)
Ranging Ballistics Computer (Scroll to bottom of page.)
This exterior ballistics computer works in conjunction with range data as well as computing a conventional drop and windage chart. Using an FFP (Final Firing Point) and multiple TRP’s (Target Reference Points) the system will simultaneously calculate Drop and Windage data for up to 30 TRP’s 360 degrees around the FFP. Windage is corrected for the TRP direction compared to the primary wind direction. The spreadsheet consists of six individual pages. Each page performs a distinct function and contains all the information required to complete a shot at a target or targets. The entire system can be used in any laptop or handheld computer capable of running MS Excel or Excel CE.
CLICK HERE to download Ranging Ballistics Computer (requires MS Excel)
Rimfire Ammo Comparison Table
Canada’s NFA even provides a detailed table with bullet weights and velocities for over 100 varieties of 22LR Rimfire ammunition from Aguila, CCI, Eley, Federal, Fiocchi, Lapua, PMC, Remington, RWS, and Winchester. This Rimfire Ammo Table is a “must-have” resource for any smallbore shooter. Shown below is the section for Lapua:
April 16th, 2009
The HuntingNut.com website offers Point Blank Ballistics and Reloading software free of charge. That’s right, the program is absolutely free, forever — not just for a trial period. We use Point Blank all the time, not just to calculate come-ups and windage for our rifles, but also to compare ballistics among various chamberings, or to compare different bullets. With Point Blank it is easy to just change your bullet BC value and instantly see the effect on windage and drop. Point Blank will even calculate muzzle energy and recoil force. Point Blank will also hold all your reloading info in a built-in database. You enter the caliber (chambering), bullet, powder, velocity, and other important variables. Then you can quickly access hundreds of different load combinations.
CLICK HERE TO download PointBlank Reloading & Ballistics Software v2.0 ZIP Archive.
(Note: this 1.13mb file is for Windows computers; you need WinZip or other program to unzip the file archive.)
You can even use Point Blank to plot your shots on a test target. This way you can easily compare the accuracy of different “recipes” during load development. You can record up to 10 shots per target.
Calculate Recoil, Muzzle Energy, Knock-Out Power
Point Blank has many other useful functions. Click on the “Misc Functions” tab, and you’ll find the program will calculate recoil and muzzle energy. If you clock bullet speed at both the muzzle and a 100-yard target, the program will also calculate actual bullet Balllistic Coefficient. For hunters, the program calculates Taylor Knock-Out values, and the program even provides handy English/Metric unit conversions.
August 30th, 2008
One of the great things about our Shooters’ Forum is that many uniquely talented shooters share their knowledge and test findings. One of those experts is “bsl135″ aka Bryan Litz. Bryan is no ordinary “weekend warrior”. He graduated from Penn State with a degree in Aerospace Engineering. He then began a career as a missile design engineer at Wright-Patterson Air Force Base. He has written many ballistics programs and technical papers dealing with long-range flight dynamics of projectiles. Bryan is also a superb long-range shooter, holding an NRA High Master Classification. At this year’s NRA National Championships at Camp Perry, Bryan beat 258 other competitors to win the Palma Individual Trophy Match. Bryan shot a remarkable 450/26x, not dropping a single point.
Breaking News: Just today, Bryan won the Ohio State Midrange Championship, an iron sights event with 15 shots each at 300, 500, and 600 yards. Bryan shot a spectacular 450/39X. Again, Bryan didn’t drop a point and his X-count would make this a new National Record, pending certification. Congrats Bryan!
Bryan also has his own website with a number of authoritative articles. Topics include: Bullet Design, Meplat Trimming, Gyroscopic and Coreolis Drift, Palma Bullet Analysis, How Ballistics Programs Work, and Ballistic Coefficient Testing. CLICK HERE to visit BRYAN LITZ Website.
7mm Bullet BC Testing — Evaluating the Numbers
Bryan does a lot of testing for bullet-makers, evaluating the performance of various bullet types. One thing he has observed is that manufacturers’ published BCs may vary considerably even for two bullet designs that appear to be nearly identical. In our Forum, Bryan offered this interesting analysis of the 7mm Berger 180gr VLD and the similar 7mm JLK 180gr VLD:
“I’ve developed a repeatable procedure for test firing bullets to determine ballistic coefficient. If you get Precision Shooting Magazine, the March issue has one of my articles about test firing the Berger .30 cal 155gr VLD. Long story short, my test procedure uses acoustic sensors in 200-yard increments to measure time of flight out to 600 or 1000 yards. My BC measurements are repeatable to within +/- 2%, usually within +/- 1%.
I have tested several 7mm bullets. Of particular interest are the Berger 180gr and JLK 180gr bullets. If you look at these bullets side by side, it’s hard to tell a difference between them. I believe the JLK bullet dies were made from the same set of prints as the Berger VLD (Design by Bill Davis of Tioga Engineering). So … why would these bullets have different [published] BCs? They’re the same weight and the same basic shape [with very minor differences in OAL and bearing surface length]. This is just the kind of smoke and mirrors that makes shooters think there is something mysterious about BCs and exterior ballistics that’s beyond the realm of human understanding. I was pleased with the results of my testing of these two bullets: the BC is virtually the same, as expected. All is right with the world.”
Drag Models — G7 is better than G1 for long-range Bullets
Most ballistics programs use the default G1 drag model. Bryan believes the G7 standard is preferrable for long-range, low-drag bullets: “Part of the reason there is so much ‘slop’ in advertised BCs is because they’re referenced to the G1 standard which is very speed sensitive. The G7 standard is more appropriate for long range bullets. Here are the results of my testing for these two bullets:
G1 BCs, averaged between 1500 fps and 3000 fps:
Berger 180 VLD: 0.659 lb/in²
JLK 180: 0.645 lb/in²
The reason the BC for the JLK is less is mostly because the meplat was significantly larger on the particular lot that I tested (0.075″ vs 0.059″; see attached drawings).
For bullets like these, it’s much better to use the G7 standard. The following BCs are referenced to the G7 standard, and are constant for all speeds.
G7 BCs:
Berger 180 VLD: 0.337 lb/in²
JLK 180: 0.330 lb/in²
Many modern ballistics programs, including the free online JBM ballistics program, are able to use BCs referenced to G7 standards. When available, these BCs are more appropriate for long range bullets.”
[Editor’s NOTE: BCs are normally reported simply as an 0.XXX number. The lb/in² tag applies to all BCs, but is commonly left off for simplicity.]
Effect of Bullet Pointing
Bryan has also tested the effect of pointing bullets. He’s determined that this does have a positive (if small) effect on ballistics. Bryan writes: “I have measured the Berger 180 VLD in both nominal and pointed meplat configurations. Pointing the meplat from 0.059″ to 0.039″ increases the G7 BC from 0.337 lb/in² to 0.344 lb/in². This results in less than 2″ difference in 1000-yard wind drift (10 mph 90°). The improvement is small, perhaps negligible for standard decimal prone targets with large scoring rings. The improvement is more significant for F-Class targets with smaller scoring rings. That being said, I do point my own Berger 180 VLDs that I shoot in prone competition. It’s fast, easy, doesn’t hurt anything, and every little bit helps.”
August 3rd, 2008
It’s great that Reloder 17 can allow shooters to boost velocities by 150 fps or more (in suitable cartridges). Pushing a bullet faster can flatten its trajectory and reduce the amount of wind drift (at a given distance). However, in our quest to shoot bullets ever faster, we must remember that higher speeds come with a price. Higher velocities can increase fouling, may accelerate throat wear, and without question, higher velocities increase recoil.
How can you determine how much added recoil you’ll get when you speed up your bullets? The FREE Point Blank software program has a feature that calculates recoil. All you have to do is type in bullet weight, muzzle velocity, powder charge, and gun weight. Then the program automatically calculates recoil energy in ft/lbs and recoil velocity in fps. To use this feature, after launching Point Blank, click the “Misc Functions” tab, then select “Calculate Recoil”.
Point Blank Software Calculates Ballistics and Much More…
Point Blank Software is very versatile. It offers a full-featured ballistics calculator that figures bullet drop and wind drift. A built-in database will hold all your load data. In addition, you can keep track of your firearms with the firearms inventory database. A target screen lets you plot shots and calculate group size. Among the miscellaneous functions, in addition to calculating recoil, Point Blank can calculate muzzle energy, “knockout factor”, and bullet sectional density. Point Blank even offers a handy English/metric measurement converter.
What does all this calculating power cost? Zero. Zip. Nada. Point Blank Software is FREE. Just click on the link below to go to the download page. Point Blank will run on any PC using Windows 95 or newer operating system.
DOWNLOAD FREE Point Blank Reloading & Ballistics Software
June 28th, 2008
Three-gun match competitor Zak Smith employs a simple, handy means to store his elevation and wind dift data — a laminated data card. To make one, first generate a come-up table, using one of the free online ballistics programs such as JBM Ballistics. You can also put the information in an Excel spreadsheet or MS Word table and print it out. You want to keep it pretty small.
Below is a sample of a data card. For each distance, the card includes drop in inches, drop in MOA, drop in mils. It also shows drift for a 10-mph cross wind, expressed three ways–inches, MOA, and mils. Zak explained that “to save space… I printed data every 50 yards. For an actual data-card, I recommend printing data every 20 or 25 yards.” But Zak also advised that you’ll want to customize the card format to keep things simple: “The sample card has multiple sets of data to be more universal. But if you make your own data card, you can reduce the chance of a mistake by keeping it simple. Because I use scopes with MILS, my own card (bottom photo) just has three items: range, wind, drop in MILS only.”
Once you have the card you can fold it in half and then have it laminated at a local office store or Kinko’s. You can keep this in your pocket, tape it to your stock, or tie the laminated card to your rifle. If you regularly shoot at both low and high elevations, you may want to create multiple cards (since your ballistics change with altitude). To learn more about ballistic tables and data cards, check out the excellent “Practical Long-Range Rifle Shooting–Part 1″ article on Zak’s website. This article offers many other insights as well–including valuable tips on caliber and rifle selection.
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.
November 7th, 2007
Hornady has announced a new, 6.5mm cartridge designed for Across-the-Course and High Power shooters, and 3-gun competitors. (We think the new round may also prove very popular with hunters and tactical shooters.) Dubbed the 6.5 Creedmoor, the cartridge is smaller than a .260 Remington (.308-size case) but larger than the 6.5×47 Lapua. Measuring 1.920″ from base to mouth, 6.5 Creedmoor brass features a 30° shoulder and minimal body taper. Case capacity is “right around 53.0 grains of H20″ according to Hornady. The 6.5 Creedmoor uses a large rifle primer and large flash hole.
Hornady says its 6.5 Creedmoor is designed to operate at “standard” .308 Winchester pressures, for increased “barrel and case life”. The 6.5 Creedmoor factory ammo is loaded to “under 60,000 psi” according to Hornady engineers. That’s quite a bit less than the 62,000 psi SAAMI max pressure limit for the .308 Winchester, or the 63,090 rated max psi of the 6.5×47 Lapua. Compared to max-loaded 6XC or 6.5×47 cases, the lower-pressure 6.5 Creedmoor should, theoretically, provide good barrel life. Dennis DeMille, who has been testing the factory 6.5 Creedmoor ammo, reports that the factory ammo is “not on the ragged edge at all–pressures are ‘sensible’, with excellent reliability as a result.”
6.5 Creedmoor Loaded Ammo Specifications
| Bullet |
COAL (max) |
Powder |
Grains |
Primer |
Velocity |
PSI |
| 120gr Amax |
2.820″ |
H4350 |
43.5 |
LrgR |
3020 fps |
under
60,000 |
| 140gr Amax
| 2.820″ |
H4350 |
41.2 |
LrgR |
2820 fps |
under
60,000 |
The new cartridge looks speedy on paper. Hornady claims its factory-loaded 6.5 Creedmoor ammo will deliver 3,020 fps with the 120gr Amax and 2,820 fps with the 140gr Amax from a 28″ barrel. Those velocities are at the extreme high end of what we’ve seen a 6.5×47 Lapua deliver with 123gr and 139gr Scenars. In the 6.5×47, with handloads, it’s more realistic to expect 2950 fps with the 123-grainer, and about 2800 with the 139. Lapua’s factory-loaded 6.5×47 rounds are considerably slower. So, it appears the 6.5 Creedmoor will enjoy a slight velocity edge over 6.5×47 handloads, and a sizeable speed advantage over Lapua 6.5×47 factory ammo (with similar bullet weights).
BALLISTICS: 6.5 Creedmoor vs. .308 Win vs. .223 REM
Background of Cartridge
 The new cartridge was conceptualized by Dave Emary, Hornady’s Senior Ballistician, and Dennis DeMille, General Manager of Creedmoor® Sports and two-time NRA National High Power Rifle Champion. Dave and Dennis wanted to provide factory-loaded ammo that would be 100% competitive with any High Power chambering, including the 6XC and 6.5×47 Lapua. The 6.5 Creedmoor was purpose-built for match rifles, including the Tubb 2000 and DPMS/Panther Arms LR Series. Its case is shorter than the 260 Remington, so you can load even the longest bullets into .308-Win length magazines. Pushing a 120gr Amax at 3000+ fps, the 6.5 Creedmoor offers a nice, flat trajectory plus good wind-bucking ability. Dennis Demille has used the prototype cartridge for many months now in a Tubb 2000 rifle. He says, the load is “moderate and very reliable. There have been no issues with stiff bolt lift or primer cratering.” The factory ammo runs “under 60,000 psi” according to Emary, and uses Hodgdon H4350 powder–43.5 grains with the 120 Amax and 41.2 grains with the 140 Amax.
Loaded 6.5 Creedmoor ammo is slated for release in January or February 2008 “at the latest”, according to Dave Emary. Ammo should be priced about $22 per box of 20 rounds, roughly the same as Hornady .308 Win match ammo. Brass, produced by Hornady in the USA, should be available by late spring. The new 120gr Amax bullet should be released very early next year.
DOWNLOAD 6.5 Creedmoor Illustrated Brochure
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