December 5th, 2017

Ballistics Linguistics: Bullet “Caliber of Ogive” Defined

Sierra Caliber of Ogive Bullet Sierra BC geometry

This article, which originally appeared in the Sierra Bullets Blog, provides a new terminology that helps describe the geometry of bullets. Once you understand the meaning of “Caliber(s) of Ogive”, you can quickly evaluate potential bullet performance by comparing listed Caliber of Ogive numeric values.

by Mark Walker, Sierra Bullets New Product Development Manager
During one of our recent product releases, we listed the “caliber of ogive” of the bullet in the product description. While some understood what that number meant, it appears that some are not aware of what the number is and why it is important. In a nutshell, the “caliber of ogive” number will tell you how sleek the front end of the bullet is. The higher the number is, the sleeker the bullet. It also makes it easy to compare the ogives of different caliber bullets. If you want to know if a certain .308 caliber bullet is sleeker than a 7mm bullet, simply compare their “caliber of ogive” numbers.

So exactly how do you figure “caliber of ogive”? If you look at the drawing of the .30 caliber 175 gr HPBT bullet #2275 (at top), you will see that the actual radius of the ogive is 2.240. If you take that 2.240 ogive radius and divide by the diameter (or caliber) of the bullet you would get 7.27 “calibers of ogive” (2.240 ÷ .308 = 7.27). (See top photo).

In a nutshell, the “caliber of ogive” number will tell you how sleek the front end of the bullet is. The higher the number is, the sleeker the bullet.

Next let’s look at the print (below) of our 6.5mm 142gr HPBT #1742 bullet for comparison. The actual radius of the ogive is 2.756. Like with the .30 caliber 175 gr HPBT bullet #2275, if you divide 2.756 by the diameter (or caliber) of the bullet you get 10.44 “calibers of ogive”.

Sierra Caliber of Ogive Bullet Sierra BC geometry

As most people know, it has been determined through testing that the 6.5mm 142gr HPBT #1742 has a significantly higher ballistic coefficient than the .30 caliber 175 gr HPBT bullet #2275. However by simply comparing the “caliber of ogive” number of each bullet you can easily see that the 6.5mm 142 gr HPBT #1742 is significantly sleeker than the .30 caliber 175 gr HPBT bullet #2275 even without firing a shot.

Some people would say why not just compare the actual ogive radius dimensions instead of using the “caliber of ogive” figure. If we were comparing only bullets of the exact same diameter, then that would be a reasonable thought process. However, that idea falls apart when you start trying to compare the ogives of bullets of different diameters. As you can see with the two bullets presented above, if we compare the actual ogive radius dimensions of both bullets the difference is not much at all.

However, once again, testing has shown that the 6.5mm 142 gr HPBT #1742 has a significantly higher BC. The only way that this significant increase shows up, other than when we fire the bullets in testing, is by comparing the “caliber of ogive” measurement from both bullets.

Hopefully this will help explain what we mean when we talk about “caliber of ogive” and why it’s a handy number to use when comparing bullets. This information will help you to make an informed decision the next time you are in the market to buy bullets.

Sierra Bullets Caliber of Ogive Bullet BC SMK

Story tip from Grant Ubl. We welcome reader submissions.
Permalink Bullets, Brass, Ammo, Reloading 5 Comments »
December 29th, 2016

Seating Strategies: How to Optimize Your Hybrid Bullets

Berger Hybrid Bullet

SHOT Show 2017 kicks off in thre weeks in Las Vegas. While at SHOT Show next month, we plan to get the “inside scoop” on new bullet designs from Berger, Hornady, Lapua, Nosler and Sierra.

A while back, 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 many seven (7) Hybrid match bullets, with weights from 155 grains up to 230 grains. Two .338-caliber OTM Tactical Hybrids were introduced in 2012 (a 250-grainer and a 300-grainer).

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.

Permalink - Videos, Bullets, Brass, Ammo No Comments »
December 29th, 2015

Hybrid Science: How to Load Hybrid Bullets for Best Accuracy

Berger Hybrid Bullet

SHOT Show 2016 kicks off in two weeks in Las Vegas. While at SHOT Show next month, we plan to get the “inside scoop” on new bullet designs from Berger, Hornady, Lapua, Nosler and Sierra.

A while back, 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 seven different Hybrid match bullets, with weights from 155 grains up to 230 grains. Two .338-caliber OTM Tactical Hybrids were introduced in 2012 (a 250-grainer and a 300-grainer).

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.

Permalink - Videos, Bullets, Brass, Ammo 2 Comments »
November 9th, 2011

Berger Adds 215gr and 230gr Hybrids to .30 Caliber Bullet Line

Berger bulletsRecently, Berger released two new .30 caliber Hybrid Target bullets, a 215-grainer and a 230-grainer. With this new pair of projectiles, Berger now offers .30 Cal Hybrids in weights of 155 gr, 168 gr, 185 gr, 200 gr, 215 gr, and 230 grains. These bullets use a Hybrid nose designed by Bryan Litz to optimize long-range performance and enhance “tunability”. The Hybrid nose starts with a tangent shape and transitions into a secant shape. This allows these bullets to be much less seating-depth sensitive (than the VLD) while at the same time the secant portion reduces drag (for a higher BC). Berger’s Eric Stecker: “It is my understanding that each of these [new Hybrid] bullets has the highest BC of any bullets in their weight class. Combine this with being easier to tune and what you get is six new projectiles that raise the performance bar for .30 cal rifles.”

Berger Bullets .30 Cal Hybrids

Berger Rolled Out 11 New Bullet Designs in 2011
This has been a busy year for Berger Bullets. It has introduced eleven (11) all-new projectile designs. In addition, Berger re-labeled two of its popular bullets. Here’s a summary of the new offerings:

  • 6mm 105 gr Hybrid Target
  • .30 cal 155 gr Hybrid Target
  • .30 cal 168 gr Hybrid Target
  • .30 cal 185 gr Juggernaut Target (Name change — this was formerly called the 185 gr Long Range BT.)
  • .30 cal 185 gr Hybrid Target
  • .30 cal 200 gr Hybrid Target
  • .30 cal 215 gr Hybrid Target
  • .30 Cal 230 gr Hybrid Target
  • .22 Cal 77 gr OTM Tactical (Name change — this is the same bullet as the .22 cal 77 gr BT Target, but it’s new to the Tactical line).
  • .30 Cal 175 gr OTM Tactical (designed for .308 Win to be a transonic-stable option.)
  • .30 Cal 185 gr Juggernaut OTM Tactical (designed as a transonic-stable option for the 300 Win Mag.)
  • .30 Cal 230 gr Hybrid OTM Tactical (designed as a supersonic option for the 300 Win Mag.)
  • .338 Cal 300 gr Hybrid OTM Tactical (this is the redesigned Gen 2 version.)
Permalink Bullets, Brass, Ammo, New Product 5 Comments »
September 6th, 2011

New Berger .30-Cal Hybrids Released — 6mm Hybrid in Testing

Having completed successful field testing, Berger is releasing two new .30-caliber Hybrid bullets, the 185gr Hybrid (part #30424) and the new 200gr Hybrid (part # 30427). The Hybrid design, developed by Bryan Litz, combines both secant-ogive and tangent-ogive shapes. This keeps drag low while making the bullet easier to tune than typical VLD style bullets. Both these new Hybrid bullets have demonstrated excellent accuracy along with outstanding long-range ballistics. The BC on the 200-grainer is extremely high, with a G1 value of 0.624 and a G7 value of 0.320. The new 185gr and 200gr Hybrids should be arriving on store shelves very soon.

Berger 185gr and 200gr .308 Hybrid Specifications
Berger Hybrid Bullet Specifications .30 caliber

Consumer Field Testing of new 6mm 105gr Hybrid, and Heavy 30s
Berger has commenced testing of its new 30 cal 215 and 230 gr Hybrid bullets, and Bergers new 6mm 105gr Hybrid. Berger tells us that: “If the tests results are positive, these bullets should be available to order in the middle of October, 2011.”

Berger is soliciting qualified AccurateShooter.com Forum members to help with the testing of the latest hybrids — the jumbo 30s and the new 6mm 105-grainer. You must have an appropriate rifle and be willing to report your results in a timely, coherent manner. In return, if selected, you’ll get a free bullets for testing — one 100-ct box per test. If you wish to participate in the testing process, click the links below to read Berger’s testing announcements in our Forum.

Berger .30-cal 215gr and 230gr Hybrid Bullet Test | Berger 6mm 105gr Hybrid Bullet Test

Story Tip by EdLongrange. We welcome reader submissions.
Permalink Bullets, Brass, Ammo, New Product 4 Comments »
March 25th, 2011

More Hybrid Bullet Designs Coming from Berger Bullets

Berger BulletsIn the Berger Bulletin this week is a further discussion of the new Berger “Hybrid” bullet design. This combines a secant ogive shape in the front of the bullet with a tangent ogive shape near the full-diameter (shank) section. Currently the Berger Hybrid is available in .338 caliber and 7mm. Berger will soon release a new hybrid .30 caliber bullet, with 6mm and 6.5mm hybrid projectiles to follow.

How the Hybrid was Developed
In the late 80s, the VLD was born. This design allowed shooters to use lighter bullets and smaller calibers to achieve the same or better trajectory than heavier bullets in bigger calibers. Lighter bullets shot in small calibers were easier on shooters resulting in higher scores and an improved shooting experience. But, this improvement came with a price. Each shooter had to adjust their load in each rifle until they could get the VLD bullet to shoot precisely. Once the load was dialed in, the VLD was one of the most efficient bullet designs in history. But this didn’t stop shooters from yearning for a bullet that is easier to tune.

The VLD design was created by Bill Davis who was one of the top ballistic minds during this time. His [designs] have made a tremendous impact on how long range shooting over the last two decades. One might think that nothing this good can be improved upon. But it could… Ballistician Bryan Litz recognized both the advantages and disadvantages of the VLD design. He went to work to see if he could keep the good results the VLD produced while reducing its sensitivity to seating depth. His efforts have produced the Berger Hybrid.

The Berger Hybrid design incorporates two different shapes within the nose. As the bearing surface ends, a tangent ogive begins. This tangent section of the ogive results in the bullet being much less sensitive to seating depth. Testing results show that the Berger Hybrid shoot equally well at either a jam or a jump. As you move forward along the tangent portion, the shape changes into a secant ogive. The secant ogive is the shape used on the VLD bullets. This shape is very efficient in the wind and is why the VLD became so popular.

By bringing these two shapes together, Bryan has successfully created a bullet that is both not sensitive to seating depth and shoots very flat like a VLD. The key to all this is not just the combining of these two shapes, but also the partnership between the ballistician and the bullet maker.

Permalink Bullets, Brass, Ammo 2 Comments »
March 16th, 2011

Tangent vs. Secant vs. Hybrid Ogive — Bryan Litz Explains

In discussions of ballistics, you’ll see references to “tangent” and “secant” bullet shapes. We know that, for many readers, these terms can be confusing. To add to the confusion, bullet makers don’t always identify their projectiles as secant or tangent designs. This article provides a basic explanation of tangent and secant designs, to help you understand the characteristics of both bullet shapes.

Tangent Ogive vs. Secant Ogive vs. Hybrid
Most match bullets produced today use a tangent ogive profile, but the modern VLD-style bullets employ a secant profile. To further complicate matters, the latest generation of “Hybrid” projectiles from Berger Bullets feature a blended secant + tangent profile to combine the best qualities of both nose shapes. The secant section provides reduced drag, while the tangent section makes the bullet easier to tune, i.e. less sensitive to seating depth position.

Berger Bullets ballistician Bryan Litz explains tangent and secant bullet ogive designs in a glossary section of his Applied Ballistics website, which we reprint below. Bryan then explains how tangent and secant profiles can be combined in a “hybrid” design.

How Bullet Ogive Curves are Defined
While the term “ogive” is often used to describe the particular point on the bullet where the curve reaches full bullet diameter, in fact the “ogive” properly refers to the entire curve of the bullet from the tip to the full-diameter straight section — the shank. Understanding then, that the ogive is a curve, how is that curve described?

LITZ: The ogive of a bullet is usually characterized by the length of its radius. This radius is often given in calibers instead of inches. For example, an 8 ogive 6mm bullet has an ogive that is a segment of a circular arc with a radius of 8*.243 = 1.952”. A .30-caliber bullet with an 8 ogive will be proportionally the same as the 8 ogive 6mm bullet, but the actual radius will be 2.464” for the .30 caliber bullet.

For a given nose length, if an ogive is perfectly tangent, it will have a very specific radius. Any radius longer than that will cause the ogive to be secant. Secant ogives can range from very mild (short radius) to very aggressive (long radius). The drag of a secant ogive is minimized when its radius is twice as long as a tangent ogive radius. In other words, if a tangent ogive has an 8 caliber radius, then the longest practical secant ogive radius is 16 calibers long for a given nose length.”

Secant Ogive vs. Tangent Ogive

tangent Secant Ogive

Ogive metrics, and Rt/R
LITZ: There is a number that’s used to quantify how secant an ogive is. The metric is known as the Rt/R ratio and it’s the ratio of the tangent ogive radius to the actual ogive radius for a given bullet. In the above example, the 16 caliber ogive would have an Rt/R ratio of 0.5. The number 0.5 is therefore the lowest practical value for the Rt/R ratio, and represents the minimum drag ogive for a given length. An ogive that’s perfectly tangent will have an Rt/R ratio of 1.0. Most ogives are in between an Rt/R of 1.0 and 0.5. The dimensioned drawings at the end of my Applied Ballistics book provide the bullets ogive radius in calibers, as well as the Rt/R ratio. In short, the Rt/R ratio is simply a measure of how secant an ogive is. 1.0 is not secant at all, 0.5 is as secant as it gets.

Hybrid Bullet Design — Best of Both Worlds?
Bryan Litz has been developing a number of modern “Hybrid” design bullets for Berger. The objective of Bryan’s design work has been to achieve a very low drag design that is also “not finicky”. Normal (non-hybrid) secant designs, such as the Berger 105gr VLD, deliver very impressive BC values, but the bullets can be sensitive to seating depth. Montana’s Tom Mousel has set world records with the Berger 105gr VLD in his 6mm Dasher, but he tells us “seating depth is critical to the best accuracy”. Tom says a change of .005″ in seating depth “can cause the group size to increase substantially”. In an effort to produce more forgiving high-BC bullets, Bryan Litz has developed a hybrid tangent/secant bullet shape. This is explained in the illustration below.

hybrid bullet

Story sourced by Edlongrange.
Permalink Bullets, Brass, Ammo, New Product 4 Comments »
January 19th, 2011

SHOT Show Report: Berger Crafts Hybrids in More Calibers

The big news at Berger Bullets for 2011 is the Hybrid. No, Walt isn’t switching to a Prius… but Berger IS committing to the dual-shape hybrid design for a full range of calibers. The hybrid design combines a secant ogive (VLD-style) profile in the front of the bullet, with a tangent profile further back. This gives bullets the high BC of the VLD-style bullets, but the tangent section makes the bullets less sensitive to small variations in seating depth. The tangent ogive is a more gentle curve. Tangent ogive bullets, generally speaking, are more “forgiving” or easier to tune. They also will stay in tune better as a barrel throat erodes.

What Berger has done with the hybrid bullet is put an easy-tuning geometry on the part of the bullet that actually engages the rifling, while using a more streamlined front end for improved ballistics. This hybrid design was introduced in 2010 with hybrid 7mm and .338 bullets. Both new hybrid designs proved very successful. The hybrid designs were developed with significant design input from Bryan Litz, Berger’s ballistician. Before Bryan signed on with Berger, he literally worked as a rocket scientist, so he knows something about low-drag shapes. In the video below, Bryan explains why Berger will introduced more hybrid bullets in more calibers, in the months ahead. Bryan also talks about other products Berger has in the works, including its much-awaited reloading manual.

YouTube Preview Image
Permalink - Videos, Bullets, Brass, Ammo, New Product 2 Comments »
October 6th, 2010

Hornady’s New 285gr .338 Bullet Wins HG at IBS Nationals

Hornady plans to release a brand new 285gr, .338-caliber match bullet within the next few weeks. This bullet, which boasts a mind-blowing 0.735 G1 BC, has already proven itself in competition. At the 2010 IBS 1000-yard Nationals in September, Scott Fletcher won the Heavy Gun (HG) group title shooting the new Hornady 285gr BTHPs. Scott’s 4-match, 10-shot per target group Aggregate was 9.148″. Scott was shooting a large wildcat, the .338 Sloan. That cartridge is nearly identical to the new .338 Norma Magnum*, which could be described as a “chopped” .338 Lapua Mag — shorter with less case capacity.

Weight is unlimited in the 1000-yard Heavy Gun class. Weight soaks up the recoil of big cartridges like the .338 Norma Magnum, making them manageable to shoot. The Big 30-Cals have long dominated this HG category, but some shooters like Fletcher are experimenting with some really big cartridge/bullet combinations, in pursuit of class-leading ballistics. We don’t know how fast Fletcher pushes his prototype Hornady 285s, but that 0.735 BC has to give the bullets awesome performance in the wind.

Artist’s concept — No photos of the new bullet are available.

.338 285grain Hornady

New Manufacturing Process Produces Bullets with Near-Zero Run-out
According to Hornady’s Chief Ballistic Scientist Dave Emary, the new 285-grainer is a VLD-style, secant ogive projectile with a standard, drawn-copper jacket and lead core. This is a BTHP, NOT a plastic tip bullet like Hornady’s A-Max designs. Emary says, “This bullet was originally developed for the military. It has just about the lowest drag possible with conventional bullet construction and ogive design.” The .338-caliber 285gr bullet is the first of two new super-low drag bullets Hornady will be releasing before the end of the year.

The new 285gr bullets are built with a new manufacturing process that improves jacket concentricity to previously unattainable levels. Emary says: “Measured along the entire jacket, these bullets have extremely low eccentricity. We measured zero to a couple ten-thousandths total run-out along the whole jacket. As a result the bullet has show truly outstanding long-range performance, with sub-half-MOA accuracy at extreme ranges.” Hornady Project Engineer (and 1K shooter) Joe Thielen added: “These bullets are specifically designed and built for long-range use, and the jackets are the some of best I’ve ever seen.”

When will the new bullets be available? End of the year at the latest. Emary says the 285s should be available “before the end of November”. When we asked Hornady Marketing guru Steve Johnson, he said “Soon. They’ll be out soon.” When pressed as to “how soon”, Steve responded: “The release is imminent… imminent”.


*The .338 Norma Magnum was originally developed by the American sport shooter Jimmie Sloan as a long-range sport shooting wildcat cartridge. It was designed to shoot the .338-caliber, 300gr Sierra MatchKing projectile from actions/magazines too short for a .338 Lapua Magnum. Sloan licensed the design to the Norma group. Both the .338 Norma Mag and the larger .338 Lapua Mag are derived from the .416 Jeffreys, but the .338 Norma Mag fits in a shorter action.
Permalink Bullets, Brass, Ammo, New Product 4 Comments »
May 6th, 2010

Berger Bullets Releases New .338 Hybrid (Dual-Ogive) Bullet

Berger .338 BulletBerger Bullets has just released its new .338-caliber “hybrid” bullet, Berger’s first-ever projectile larger than .30 caliber. The new bullet has a very high ballistic coefficient (BC): 0.891 under the G1 model, and 0.455 under the newer G7 standard for boat-tail bullets. That high BC should translate into exceptional long-range performance. According to Berger, the BC of the new Berger .338 bullet BC is roughly 14% better than the BCs of other .338-caliber 300gr offerings from Sierra and Lapua. This claim is supported by testing done on all three bullets and published in a detailed Bullet Comparison Report (PDF). The new .338 Hybrid bullets will be sold in 50-count and 250-count boxes. To order, call Berger’s Tech-Line, (714) 447-5458.

The key design feature of the new .338 bullet is its hybrid ogive, i.e. a shape that combines both tangent and secant geometry. A tangent ogive meets the bearing surface very smoothly, whereas a secant ogive has an abrupt juncture with the bearing surface. The figure below shows the geometric differences between a tangent and a secant ogive, as well as the strengths and weaknesses of each.

Berger .338 hybrid bullet

Practical Considerations — Load Length and Twist Rate
The superior ballistic performance of the 300gr Hybrid .338 is primarily due to the very long ogive and boat tail. However, that super-long bullet length can create some issues. Berger’s new .338 Hybrid bullets are so long that loaded rounds may not fit some magazines comfortably, unless you deep-seat the bullets, which cuts down on usable case capacity. If your loaded rounds with the new .338s are too long for your magazine, single-feeding is recommended. In addition, and this is IMPORTANT, to get optimal performance with the new bullets, you may want to extend the throat in your chamber. This can be done relatively easily by a competent gunsmith using a throating reamer. We caution, however, once the throat is pushed out, you can’t go back to a shorter throat without setting back the entire barrel.

The new .338 Hybrid bullets should stabilize well with a 1:10″ twist at the velocities achievable with popular .338 magnum cartridges. However, according to Bryan Litz, Berger’s Ballistician, at extreme long ranges (beyond one mile), as the .388 bullet goes trans-sonic, it may need more spin. As the bullet slows down into the trans-sonic range, extra stability is required — something you get by spinning the bullet faster. So, for those guys planning to shoot at one mile or beyond, Berger recommends a faster twist-rate. The faster twist provides more spin-stabilization at very long ranges. But for 1000-yard shooting, you don’t need to be concerned about trans-sonic stability. As Bryan explains: “So as long as you keep your shots under 1 mile, the 1:10″ twist is plenty adequate.”

Berger Bullets Video Update (Eric Stecker talks about the new .338 Hybrid and other matters.)
YouTube Preview Image

Permalink - Videos, Bullets, Brass, Ammo, New Product 4 Comments »