In discussions of ballistics, you’ll see references to “tangent”, “secant”, and “hybrid” 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, secant, and hybrid ogive bullet designs, to help you understand the characteristics of these three basic bullet shapes.
Tangent vs. Secant 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 bullet 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.”
Bryan Litz Explains Hybrid Design and Optimal Hybrid Seating Depths
Ogive Metrics and Rt/R Ratio
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 developed 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 mere .003″ seating depth change “makes a difference”. In an effort to produce more forgiving high-BC bullets, Bryan Litz developed the hybrid tangent/secant bullet shape.
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In discussions of ballistics, you’ll see references to “tangent”, “secant”, and “hybrid” 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, secant, and hybrid ogive bullet designs, to help you understand the characteristics of these three basic bullet shapes.
Tangent vs. Secant 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 bullet 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.”
Bryan Litz Explains Hybrid Design and Optimal Hybrid Seating Depths
Ogive Metrics and Rt/R Ratio
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 developed 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 mere .003″ seating depth change “makes a difference”. In an effort to produce more forgiving high-BC bullets, Bryan Litz developed the hybrid tangent/secant bullet shape.
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Noted gun writer Glen Zediker (author of Top Grade Ammo), regularly contributes tech articles to the Midsouth Shooters Blog. One of Glen’s Midsouth Blog articles covers Bullet Design. We suggest you read the article — even seasoned hand-loaders will learn a few things about projectile properties (and how to choose the right bullet design for your needs). Glen also wrote a recent Blog article on cartridge pressure signs, linked below
Glen explains: “A ‘match’ bullet’s job is to perforate a piece of paper. A bullet designed for varmint hunting, on the other hand, is designed to produce explosive impact, and one for larger game hunting strives to strike a balance between expansion and penetration. However! No matter how it’s built inside, there are universal elements of any bullet design, and those are found on the outside.”
In his article, Glen identifies the key elements of a bullet and explains how they are defined: “Base, that’s the bottom; boat-tail, or not (flat-base); shank, portion of full-caliber diameter; ogive, the sloping ‘nosecone'; tip, either open or closed (open it’s called the ‘meplat’). The shape of the ogive and the first point of ‘major diameter’ are extremely influential elements. The first point of major diameter can vary from barrel brand to barrel brand because it’s the point on the bullet that coincides with land diameter in the barrel — the first point that will actually contact the barrel as the bullet moves forward. When there’s a cartridge sitting in the rifle chamber, the distance or gap between the first point of major diameter and the lands is called ‘jump’, and, usually, the less there is the better.”
Ogives Analyzed — Tangent vs. Secant Bullet Designs
Glen notes that bullet designs reflect secant or tangent profiles, or a combination of both: “The two essential profiles a bullet can take are ‘secant’ and ‘tangent’. This refers to the shape of the ogive. A tangent is a more rounded, gradual flow toward the tip, while a secant is a more radical step-in, more like a spike. Secants fly with less resistance (less aerodynamic drag), but tangents are [often] more tolerant of jump [or to put it another way, less sensitive to seating depth variations].”
Glen adds: “Ogives are measured in ‘calibers’. That’s pretty simple: an 8-caliber ogive describes an arc that’s 8 times caliber diameter; a 12-caliber is based on a circle that’s 12 times the caliber. The 8 will be a smaller circle than the 12, so, an 8-caliber ogive is more ‘blunt’ or rounded. Bullets with lower-caliber ogives are more tolerant of jump and (usually) shoot better, easier. Higher-caliber ogives [generally] fly better, farther. This is an important component in the ‘high-BC’ designs.”
Learn More in Zediker Books
Glen has authored a number of excellent books for hand-loaders and competitive shooters. Here are three of his most popular titles, including his latest book, Top Grade Ammo:
All these titles are available from Midsouth Shooters Supply. Click each cover above to purchase from Midsouth.
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In discussions of ballistics, you’ll see references to “tangent”, “secant”, and “hybrid” 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, secant, and hybrid ogive bullet designs, to help you understand the characteristics of these three basic bullet shapes.
Tangent vs. Secant 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 bullet 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.”
Bryan Litz Explains Hybrid Design and Optimal Hybrid Seating Depths
Ogive Metrics and Rt/R Ratio
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 developed 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 mere .003″ seating depth change “makes a difference”. In an effort to produce more forgiving high-BC bullets, Bryan Litz developed the hybrid tangent/secant bullet shape.
Story sourced by Edlongrange.
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Need bullets for your 2018 High Power Campaign, F-Class Matches, PRS Comps, or Varmint Safaris? Check out this deal at Midsouth Shooters Supply. Now through March 18, 2018 at 11:59 pm, Midsouth has knocked ten percent (10%) off the price off all Sierra Bullets in stock. And Midsouth’s prices were already very competitive. The sale applies to all Sierra projectiles for rifles and pistols: match bullets, hunting bullets, varmint bullets, self-defense bullets.
This is your opportunity to grab some of Sierra’s great new generation MatchKing bullets. Many of these new SMKs come with the bullets “tipped” at the factory for more uniform BC. We have hear very positive comments from shooters running the tipped SMKs in .30 Caliber, 7mm, 6.5 mm, and 6mm. If you are shooting F-Open, you should definitely try the new 197gr MatchKing, with its stellar 0.780 G1 BC. Likewise if you shoot PRS or mid-range benchrest, you should check out the new 110gr SMK. It boasts an impressive 0.617 G1 BC.
More High-BC MatchKings in All Your Favorite Calibers
Sierra now offers very slippery, heavy-for-caliber MatchKings that have raised the BC Bar for their respective calibers. For example, the 150gr 6.5mm bullet really “pushes the envelope”. In past years, 140-142 grains was considered “high end” for a 6.5mm match projectile. Here are Sierra’s BC Leaders for 6mm, 6.5mm, 7mm, and .308 calibers. Many of these New Generation MatchKings now come “tipped” from the factory for more uniform BC.
Heavy-for-Caliber, Ultra-High BC Sierra MatchKings
In recent months, Sierra has unveiled four very serious, ultra-high-BC MatchKing bullets in .224, .264 (6.5 mm), and .308 calibers. And just last week Sierra has released initial load data for these four new projectiles. CLICK HERE to get the latest official load data for these four new bullets.
High-BC MatchKings Tipped at Factory
Sierra recently released a new-for-2018, 95-grain .224 projectile, Sierra product #1396, with a claimed G1 BC of 0.600 — mighty impressive for a .22-caliber bullet. Next up is the new 6.5mm (.264 caliber) 150-grainer with an 0.713 G1 BC. This could be a game-changer for the 6.5-284 and new 6.5 PRC short magnum. There are also two new .308-caliber MatchKings, a 200-grainer with 0.715 G1 BC, and a new 230-grainer with a stunning 0.800 G1 BC. Many of these New Generation MatchKings now come “tipped” from the factory for more uniform BC.
Sierra Bullets has LOAD DATA for these four new bullets. If you handload for .223 Remington, 22-250, 6.5 x284 Norma, .308 Winchester, or .300 Winchester Magnum, check out this new reloading data.
We know many of our readers aren’t 100% clear on the difference between a secant ogive bullet and a tangent ogive bullet. Add the “blended” or “hybrid” ogive into the design equation and you add to the confusion. In this article, Berger Ballistician Bryan Litz, explains the characteristics of the three popular ogive types: tangent, secant, and hybrid.
In discussions of ballistics, you’ll see references to “tangent” and “secant” bullet shapes. 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 vs. Secant 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 bullet 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.”
Ogive Metrics and Rt/R Ratio
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 developed 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 mere .003″ seating depth change “makes a difference”. In an effort to produce more forgiving high-BC bullets, Bryan Litz developed the hybrid tangent/secant bullet shape.
Bryan Litz Explains Hybrid Design and Optimal Hybrid Seating Depths
Story sourced by Edlongrange.
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SHOT 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 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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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
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.