December 27th, 2018

Chronos by The Numbers — Tips on ES, SD, and Sample Sizes

USAMU Marksmanship Unit Velocity Chronograph Testing Sample Sizes

The U.S. Army Marksmanship Unit (USAMU) regulary publishes “how-to” articles on the USAMU Facebook page. One informative “Handloading Hump Day” article covers chronograph testing and statistical samples. We highly recommend you read this article, which offers some important tips that can benefit any hand-loader. Visit the USAMU Facebook page next Wednesday for the next installment.

Chronograph Testing — Set-Up, Sample Sizes, and Velocity Factors

Initial Chronograph Setup
A chronograph is an instrument designed to measure bullet velocity. Typically, the bullet casts a shadow as it passes over two electronic sensors placed a given distance apart. The first screen is the “start” screen, and it triggers an internal, high-speed counter. As the bullet passes the second, or “stop” screen, the counter is stopped. Then, appropriate math of time vs. distance traveled reveals the bullet’s velocity. Most home chronographs use either 2- or 4-foot spacing between sensors. Longer spacing can add some accuracy to the system, but with high-quality chronographs, 4-foot spacing is certainly adequate.

Laboratory chronographs usually have six feet or more between sensors. Depending upon the make and model of ones chronograph, it should come with instructions on how far the “start” screen should be placed from one’s muzzle. Other details include adequate light (indoors or outdoors), light diffusers over the sensors as needed, and protecting the start screen from blast and debris such as shotgun wads, etc. When assembling a sky-screen system, the spacing between sensors must be extremely accurate to allow correct velocity readings.

Statistics: Group Sizes, Distances and Sample Sizes
How many groups should we fire, and how many shots per group? These questions are matters of judgment, to a degree. First, to best assess how ones ammunition will perform in competition, it should be test-fired at the actual distance for which it will be used. [That means] 600-yard or 1000-yard ammo should be tested at 600 and 1000 yards, respectively, if possible. It is possible to work up very accurate ammunition at 100 or 200 yards that does not perform well as ranges increase. Sometimes, a change in powder type can correct this and produce a load that really shines at longer range.

The number of shots fired per group should be realistic for the course of fire. That is, if one will be firing 10-shot strings in competition then final accuracy testing, at least, should involve 10-shot strings. These will reflect the rifles’ true capability. Knowing this will help the shooter better decide in competition whether a shot requires a sight adjustment, or if it merely struck within the normal accuracy radius of his rifle.

How many groups are needed for a valid test? Here, much depends on the precision with which one can gather the accuracy data. If shooting from a machine rest in good weather conditions, two or three 10-shot groups at full distance may be very adequate. If it’s windy, the rifle or ammunition are marginal, or the shooter is not confident in his ability to consistently fire every shot accurately, then a few more groups may give a better picture of the rifle’s true average.

(more…)

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December 16th, 2018

G1 vs. G7 Ballistic Coefficient Models — What You Need to Know

G1 G7 BC drag models

Over the past 12 months, this article was one of the TOP TEN most-read Daily Bulletin features. We’re reprising it today for those who may have missed it the first time. The above diagram comes from a TiborasurasRex YouTube Video comparing G1 and G7 BC models. CLICK HERE to watch the video.

The better, up-to-date ballistics programs let you select either G1 or G7 Ballistic Coefficient (BC) values when calculating a trajectory. The ballistic coefficient (BC) of a body is a measure of its ability to overcome air resistance in flight. You’ve probably seen that G7 values are numerically lower than G1 values for the same bullet (typically). But that doesn’t mean you should select a G1 value simply because it is higher.

Some readers are not quite sure about the difference between G1 and G7 models. One forum member wrote us: “I went on the JBM Ballistics website to use the web-based Trajectory Calculator and when I got to the part that gives you a choice to choose between G1 and G7 BC, I was stumped. What determines how, or which one to use?”

The simple answer is the G1 value normally works better for shorter flat-based bullets, while the G7 value should work better for longer, boat-tailed bullets.

G1 vs. G7 Ballistic Coefficients — Which Is Right for You?
G1 and G7 refer both refer to aerodynamic drag models based on particular “standard projectile” shapes. The G1 shape looks like a flat-based bullet. The G7 shape is quite different, and better approximates the geometry of a modern long-range bullet. So, when choosing your drag model, G1 is preferrable for flat-based bullets, while G7 is ordinarily a “better fit” for longer, boat-tailed bullets.

G1 G7 Ballistic coefficients

Drag Models — G7 is better than G1 for Long-Range Bullets
Many ballistics programs still offer only the default G1 drag model. Bryan Litz, author of Applied Ballistics for Long Range Shooting, 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’s the results of my testing on two low-drag, long-range boat-tail bullets, so you can see how the G1 and G7 Ballistic coefficients compare:

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, according to Bryan.

[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.]

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May 5th, 2017

.22 LR Ammo Performance — ELEY Offers Online Lot Analyzer

ELEY Lot Analyzer online database

How good is .22 LR rimfire ammo you just bought? Well, until now, you had to just cross your fingers and do your own testing (unless you could make the journey to the Eley or Lapua test centers). Now that’s changed. In a matter of seconds, you can access tons of test data for Eley rimfire ammo, seeing how any given lot has performed, and how consistent it has proven. You can view a wealth of data, including group size, percentage of shots within tenths of inches from center, velocity and more. There’s even a 50-shot consolidated group display that conveniently reveals large sample accuracy in a glance. With ELEY’s new web-based Lot Analyzer, you can easily compare various lot numbers, choosing the one that shows the best test results.

ELEY Lot Analyzer online database

With the ELEY Lot Analyzer, simply enter any ELEY lot number into the online database. You’ll then see a heap of information including 10-Shot Groups, 50-Shot Groups, Average Velocity, Ballistics Coefficient, Shot Distribution graphs, and even the Eley Coin Test — the percentage of this lot capable of hitting a dime at 54.7 yards (50m). We believe the ELEY Lot Analyzer delivers the most comprehensive lot-specific ammo performance information ever provided by any ammunition manufacturer.

ELEY Lot Analyzer online database

ELEY is to be commended for making this information available. Shown below are some of the data views available for ELEY Force ammo Lot 3H16-30356:

ELEY Lot Analyzer online database

Try It Yourself with Lot Number 1016-02107
To see how the ELEY Lot Analyzer works first-hand, CLICK HERE and enter this lot number 1016-02107 (be sure to include the dash).

Lot Analyzer Data Available from 2015 Forward
We think the ELEY Lot Analzyer is great for the consumer. It is now possible to select a box of ammo from a store shelf, enter the ELEY lot number, and instantly see the performance of the ammunition. Get together with fellow shooters and compare your ELEY ammo. This service will be available for all ELEY lot numbers in the USA from 2015 forward. You can find the year of your ammunition by the third and fourth numbers in the lot. For example, if your lot number is 3016-30xxx, it is from the year 2016.

EDITOR’s NOTE — Test Center Performance vs. the Real World:
Our staff has tested rimfire ammo in both the ELEY and Lapua Test Centers, and then shot that same ammo later in competition at outdoor ranges. We learned something in the process. First, ammo can do well in a test tunnel, with a clamped test fixture, yet perform very differently outdoors on a real range. Likewise, ammo may shoot superbly in one rifle, yet perform so-so in another rifle, even when the barrels are from the same manufacturer.

We commend ELEY for providing the Lot Analyzer — this really does offer invaluable information to the consumer. This represents a big step forward. That said, you need to understand that factory test results cannot necessarily be duplicated in the real world. And we can confirm that some ammo which was less than stellar in the test tunnel actually shot superbly in real rimfire benchrest competition. LESSON: Even with the ELEY Lot Analyzer, you still need to do your own testing, with your own rifle, to verify .22 LR ammo performance.

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October 22nd, 2015

Berger Updates Bullet BC Data and Recommended Twist Rates

Berger BC Ballistics Coefficient Barrel Twist Rate  Updates

Berger has released two important informational updates for its line-up of bullets. First, the Ballistics Coefficients (BCs) have been updated for the vast majority of bullets Berger sells. In addition, G7 model BCs are being provided for most of the bullets. You will want to use the updated BC data, which is based on actual testing of recent production lots of bullets.

Second, Berger is now providing a dual twist-rate recommendation for most bullets. Berger is now lists a “minimum” barrel twist rate as well as an “optimal” twist rate. To get maximum long-range performance from your bullets, use a barrel with the “optimal” rate of twist.

CLICK HERE for the latest Berger Quick Reference Sheets with updated BCs and new Optimal Twist Rates. Eric Stecker, Berger President says: “We have tested every lot of bullets‬ produced in the last several years to bring you these updated numbers for all of our bullets.”

Ballistic Coeffificent (BC) Updates with G7 Data
Berger notes: “We have updated all of our Ballistic Coefficients to be even more accurate.
Prior to 2008, all of Berger Bullets’ BCs were calculated using a computer prediction. Early in 2009, we began measuring BCs with live-fire testing. As a result, Berger’s BCs were updated and G7 BCs were also made available. This represented a dramatic improvement in the accuracy of performance data at that time. Since 2009, the BCs assessed for Berger Bullets have not been updated. As part of our ongoing effort to provide shooters with the best information possible, Berger has been testing every lot of bullets produced for the last several years. The result is updated and highly accurate running averages of BCs for recent production lots.

Here are some of the Updated BC Values for popular Berger Target (Match) Bullets:

Description New G1 BC New G7 BC % Change
22 Cal 80gr VLD Target 0.455 0.233 +2%
22 Cal 90gr VLD Target 0.534 0.274 -3%
6mm 95gr VLD Target 0.467 0.240 -3%
6mm 105gr VLD Target 0.517 0.265 +5%
6mm 105gr Hybrid Target 0.536 0.275 -1%
6mm 115gr VLD Target 0.563 0.289 +3%
6.5mm 130gr VLD Target 0.562 0.288 +2%
6.5mm 140gr Hybrid Target 0.607 0.311 -2%
7mm 180gr VLD Target 0.683 0.350 +4%
7mm 180gr Hybrid Target 0.680 0.349 +1%
30 Cal 155gr Hybrid Target 0.478 0.245 -1%
30 Cal 185gr Hybrid Target 0.576 0.295 +1%
30 Cal 215gr Hybrid Target 0.691 0.354 -1%

CLICK HERE for Complete Table with all bullets on Berger Website

G7 Form Factor Addition
Berger also added the G7 form factor to the Ballistics Quick Reference Sheet. The analysis of form factors can be very useful when considering a bullet’s long range performance potential. Going by BC alone can be deceptive since BC includes the weight and caliber of the bullet. Form factor indicates how much drag the bullet has, which is a very important consideration for all bullets of all calibers.

NEW Dual Twist-Rate Recommendations
Recommended twist rates for bullets are commonly listed as a single value, such as 1:12” (one rotation in 12″ of barrel travel). This may be overly simplistic. There is a big gray area of marginal stability in which bullets can fly with good accuracy, but with a reduced (i.e. sub-optimal) Ballistic Coefficient. Recognizing this reality, Berger is now listing two twist rates for each bullet it makes. The first is the minimum twist needed for good accuracy, which Berger has always recommended. The second is the new optimal twist rate, which is the twist that will stabilize the bullet to a level which achieves its full performance (BC) potential. CLICK HERE For more information.

Berger BC Ballistics Coefficient Barrel Twist Rate  Updates

Permalink Bullets, Brass, Ammo, Tech Tip 6 Comments »
September 12th, 2015

Coefficient Conundrum: G1 vs. G7, Which BC Should You Use

The better, up-to-date ballistics programs let you select either G1 or G7 Ballistic Coefficient (BC) values when calculating a trajectory. The ballistic coefficient (BC) of a body is a measure of its ability to overcome air resistance in flight. You’ve probably seen that G7 values are numerically lower than G1 values for the same bullet (typically). But that doesn’t mean you should select a G1 value simply because it is higher.

Some readers are not quite sure about the difference between G1 and G7 models. One forum member wrote us: “I went on the JBM Ballistics website to use the web-based Trajectory Calculator and when I got to the part that gives you a choice to choose between G1 and G7 BC, I was stumped. What determines how, or which one to use?”

The simple answer to that is the G1 value normally works better for shorter flat-based bullets, while the G7 value should work better for longer, boat-tailed bullets.

G1 vs. G7 Ballistic Coefficients — Which Is Right for You?
G1 and G7 refer both refer to aerodynamic drag models based on particular “standard projectile” shapes. The G1 shape looks like a flat-based bullet. The G7 shape is quite different, and better approximates the geometry of a modern long-range bullet. So, when choosing your drag model, G1 is preferrable for flat-based bullets, while G7 is ordinarily a “better fit” for longer, boat-tailed bullets.

G1 G7 Ballistic coefficients

Drag Models — G7 is better than G1 for Long-Range Bullets
Many ballistics programs still offer only the default G1 drag model. Bryan Litz, author of Applied Ballistics for Long Range Shooting, 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’s the results of my testing on two low-drag, long-range boat-tail bullets, so you can see how the G1 and G7 Ballistic coefficients compare:

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, according to Bryan.

[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.]

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May 9th, 2015

Litz Field-Tests BCs of Sierra Tipped MatchKings

Following Sierra’s introduction of Tipped MatchKing (TMK) bullets, Bryan Litz of Applied Ballistics LLC has received many requests to determine the Ballistic Coefficient (BC) of these bullets through testing. Below are Litz’s findings for four out of the six bullets he has able to acquire and test so far.

Sierra Tipped MatchKing TMK Bullets Applied Ballistics G1 and G7 BC Coefficient

As you can see from the above table, when Sierra’s G1 BC is averaged for all speed ranges (which is representative of long range shooting) the results closely match the Applied Ballistics’ measurements of the same bullets, averaged from 3000 to 1500 FPS. The G7 BC doesn’t suffer nearly the velocity sensitivity as G1 and should be used for modern long range bullets when possible. Bryan tells us: “When I get the .22 caliber 77gr, and the .308 caliber 168gr tested, I’ll update the table.”

How do these Tipped MatchKings compare to standard MatchKings? According to Bryan’s measurements, here are some comparisons:

  • The 69gr TMK BC is +8% compared to the 69gr SMK
  • The 125gr TMK BC is -5% compared to the 125gr SMK (Litz believes this SMK was ‘pointed’)
  • The 155gr TMK BC is identical to that of the 155gr SMK (#2156, which is also pointed)
  • The 175gr TMK BC is +10% compared to the 175gr SMK

Bryan provided this additional advice for users of Ballistics programs: “Sierra’s stated BCs are measured by live fire, and are typically pretty accurate if the velocity bands are properly observed (7mm being the exception). A common error is to look at the BC that Sierra gives for your MV and just use that. Doing so overestimates the performance of the bullets over long range, and will cause you to hit low compared to your trajectory predictions.”

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December 18th, 2014

NEW Tipped MatchKing (TMK) Bullets from Sierra

Sierra has announced a new line of plastic-tipped MatchKing bullets. “Say What!? — that can’t be right…” you may be thinking. MatchKings have always been jacketed, hollowpoint bullets. Until now, plastic tips have been reserved for other Sierra projectiles, such as BlitzKing varmint bullets. But that is changing with the introduction of Sierra’s line of Tipped MatchKing (TMK) bullets featuring green acetal resin tips.

.308 30 caliber Sierra bullets tipped matchking TMK SMK

Plastic Tips Offer Better BC
Sierra says the plastic tips on TMKs enhance the Ballistic Coefficient (BC): “The major advantage of adding a tip to the bullet is the reduction of drag, producing a more favorable ballistic coefficient.” Stated BCs for the new TMK bullets are listed below. These BC numbers look good, and they have been verified with real-world testing: “We shot [all the new TMKs] multiple times (we actually test our BC numbers instead of letting a computer tell us what it is) and those numbers are all proven out!”

There will be six (6) new TMK bullets, two in .224 caliber, and four in .308 caliber. The six new tipped bullet types should be available in “early 2015″. Sorry, Sierra will not be offering 6mm, 6.5mm, or 7mm TMKs for the time being, although Sierra will introduce more TMK varieties in the future. Currently, Sierra is focusing on “the most popular calibers”. Notably, the new 22-Cal 77gr TMK has a 0.420 BC — identical to the BC of Sierra’s 80gr non-tipped HPBT MatchKing. So, you get the BC of a heavier bullet in a lighter projectile that can be pushed faster. That’s big news for .223 Rem and 22-250 shooters.

Bullet Name (Click for ballistic coefficients) Brand Item BC (G1)
.224 dia. 69 gr. Tipped MatchKing (TMK) .224 dia. 69 gr. Tipped MatchKing (TMK) Tipped MatchKing 7169 .375 @ 2700+ fps
.224 dia. 77 gr. Tipped MatchKing (TMK) .224 dia. 77 gr. Tipped MatchKing (TMK) Tipped MatchKing 7177 .420 @ 2400+ fps
.308 dia. 125 gr. Tipped MatchKing (TMK) .308 dia. 125 gr. Tipped MatchKing (TMK) Tipped MatchKing 7725 .343 @ 2580+ fps
.308 dia. 155 gr. Tipped MatchKing (TMK) .308 dia. 155 gr. Tipped MatchKing (TMK) Tipped MatchKing 7755 .519 @ 1900+ fps
.308 dia. 168 gr. Tipped MatchKing (TMK) .308 dia. 168 gr. Tipped MatchKing (TMK) Tipped MatchKing 7768 .535 @ 2050+ fps
.308 dia. 175 gr. Tipped MatchKing (TMK) .308 dia. 175 gr. Tipped MatchKing (TMK) Tipped MatchKing 7775 .545 @ 2400+ fps

New Bullet Shapes Along with Plastic Tips
In addition to the bullet tip, some of these new TMK bullets have slightly modified shapes compared to previous-generation, non-tipped MatchKings (SMKs) of like caliber/weight. Sierra’s technicians reported: “The [plastic] point on the tip is smaller than the meplat on a SMK and if you look, you will also see the ogive on most of these [new TMKs] have been changed as well. Most of the big BC gains are from the reshaped ogives from the legacy SMK product.”

TMK 7169 69 gr
TMK 7177 77 gr
TMK 7725 125 grTMK 7755  155 gr
TMK 7768 168 gr
TMK 7775 175 gr

.308 30 caliber Sierra bullets tipped matchking TMK SMK

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September 21st, 2013

Lapua Releases Doppler Radar Data for Lapua Scenar-L Bullets

Lapua has done extensive field testing of its bullets, using sophisticated Doppler radar equipment. Employing radar, Lapua has logged actual observed trajectories with a variety of bullet and cartridge types. And Lapua has just released updated radar data for Scenar-L bullets used with 6.5×47 Lapua, 6.5×55 Swede, and .308 Winchester chamberings. You’ll find this new data incorporated into Lapua’s product description tables for these three cartridge types.

Lapua doppler radar dataYou will also find both G1 and G7 BCs for the new line of Scenar-L Bullets in Lapua’s updated Components Table. Ballistic coefficients are based on Doppler radar data and calculated by Quick Target Unlimited Lapua Edition.

To find the BC for a particular bullet, go to the Components Table, select the caliber (on the left) and then look for the G1 or G7 value on the right for particular bullets. For example, the BCs for the new 136gr 6.5mm Scenar-L are 0.545 (G1) and 0.274 (G7).

If you are looking for the most precise trajectory predictions, nothing beats real-world testing like this. Bullet BCs can be calculated, “on paper”, from bullet size, weight, and shape. However, in the ‘real world’ the actual aerodynamic drag forces acting on the bullet change with velocity and other variables. Therefore, a bullet’s BC is NOT actually constant at every point in its flight path. Doppler radar allows Lapua to observe the actual drop of bullets at multiple points along their trajectory.

How much more precise are Doppler-radar-based trajectory predictions than typical drop charts based on modeled BCs? Consider this… when you plug the radar-based numbers for a .338 Lapua Magnum into Lapua’s ballistics software, the error in elevation is less than 2.5 cm (1″) at 1,500 meters. By contrast, the error based on a traditional G1 BC model could be over 1 meter (i.e. more than 40 inches).

Lapua doppler radar data

Free Lapua Ballistics Software for Android OS Devices
If you want to use Lapua’s Doppler Radar data for your own ballistics calculations — there’s a App for that. Lapua’s Quick Target Unlimited (QTU) software for Android OS can be downloaded for free from the Android Market. Predicted trajectories for this software are based on precise Doppler radar ballistic measurements of Lapua bullets, making this program much more accurate than other ballistic programs for mobile phones. Note, however, the Doppler Radar data is offered ONLY for Lapua-made bullets. This App does NOT include radar data for Berger, Sierra or other brands of bullets.

Lapua doppler radar data

Product tip from EdLongrange. We welcome reader submissions.
Permalink Bullets, Brass, Ammo, News 3 Comments »
January 7th, 2013

G1 vs. G7 Ballistic Coefficients — What You Need to Know

The better, up-to-date ballistics programs let you select either G1 or G7 Ballistic Coefficient (BC) values when calculating a trajectory. The ballistic coefficient (BC) of a body is a measure of its ability to overcome air resistance in flight. You’ve probably seen that G7 values are numerically lower than G1 values for the same bullet (typically). But that doesn’t mean you should select a G1 value simply because it is higher.

Some readers are not quite sure about the difference between G1 and G7 models. One forum member wrote us: “I went on the JBM Ballistics website to use the web-based Trajectory Calculator and when I got to the part that gives you a choice to choose between G1 and G7 BC, I was stumped. What determines how, or which one to use?”

The simple answer to that is the G1 value normally works better for shorter flat-based bullets, while the G7 value should work better for longer, boat-tailed bullets.

G1 vs. G7 Ballistic Coefficients — Which Is Right for You?
G1 and G7 refer both refer to aerodynamic drag models based on particular “standard projectile” shapes. The G1 shape looks like a flat-based bullet. The G7 shape is quite different, and better approximates the geometry of a modern long-range bullet. So, when choosing your drag model, G1 is preferrable for flat-based bullets, while G7 is ordinarily a “better fit” for longer, boat-tailed bullets.

G1 G7 Ballistic coefficients

Drag Models — G7 is better than G1 for Long-Range Bullets
Many ballistics programs still offer only the default G1 drag model. Bryan Litz, author of Applied Ballistics for Long Range Shooting, 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’s the results of my testing on two low-drag, long-range boat-tail bullets, so you can see how the G1 and G7 Ballistic coefficients compare:

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, according to Bryan.

[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.]

Permalink Bullets, Brass, Ammo, Reloading 20 Comments »
January 2nd, 2013

Berger Hybrid Bullets — What You Need to Know

2013 SHOT Show Las VegasSHOT Show 2013 kicks off in two weeks in Las Vegas. One of our top priorities is to talk with the bullet makers from Berger, Hornady, Lapua, and Nosler.

At SHOT Show 2012 we chatted with Berger Ballistician Bryan Litz about Berger’s popular line of Hybrid bullets. Berger now offers a wide range of Hybrids in multiple calibers and weights. In fact, for .30-Caliber shooters, Berger now offers six different Hybrid match bullets, with weights from 155 grains up to 230 grains. New .338 Cal Tactical Hybrids were released in 2012 and big .375 Cal, and .408 Cal Hybrids are in the works (read more below).

Bryan tells us: “The hybrid design is Berger’s solution to the age old problem of precision vs. ease of use. This design is making life easier for handloaders as well as providing opportunities for commercial ammo loaders who need to offer a high performance round that also shoots precisely in many rifles with various chamber/throat configurations.”

For those not familiar with Hybrid bullets, the Hybrid design blends two common bullet nose shapes on the front section of the bullet (from the tip to the start of the bearing surface). Most of the curved section of the bullet has a Secant (VLD-style) ogive for low drag. This then blends in a Tangent-style ogive curve further back, where the bullet first contacts the rifling. The Tangent section makes seating depth less critical to accuracy, so the Hybrid bullet can shoot well through a range of seating depths, even though it has a very high Ballistic Coefficient (BC).

In the video we asked Bryan for recommended seating depths for 7mm and .30-Caliber Hybrid bullets. Bryan advises that, as a starting point, Hybrid bullets be seated .015″ (fifteen thousandths) off the lands in most barrels. Watch the video for more tips how to optimize your loads with Hybrid bullets.

Berger Hybrid Bullet

Berger is Developing New Large-Caliber and Hunting Hybrids
In related news, Berger announced that it will be offering a series of .338-caliber Hybrids. First Berger is reintroducing the Gen 1 .338 Cal, 300gr Hybrid bullet in Berger’s Hunting line. Berger will also be making a 250gr Hybrid Hunting bullet using the same type of jacket as the original Gen 1 300gr Hybrid bullet. In addition, Berger has released a .338 Cal 250gr Match Hybrid OTM Tactical bullet, along with a 300gr Match Hybrid OTM Tactical projectile.

More big bullets are on the drawing board. Our source says “.375 Caliber and then .408 Caliber are the next new calibers to be made at Berger”. These are in the design phase, and Berger needs to build a new machine, so the .375s and .408s will not be available until 2013 at the earliest.

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