| Ballistic Coefficient Calculator Form | |
| Bullet Weight (grains) | |
| Bullet Diameter (.223, .308) | |
| Bullet Shape | [?] [?] [?] [?] [?] |
| Ballistic Coefficient: | |
Important: Since there are thousands of bullet shapes the Ballistic Coefficient calculations made below are not 100% accurate, if you are shooting out past 400-500+ yards your going to need to get the exact BC from the bullet's manufacturer. We are working on a massive list, but this list won't be ready for a few weeks or months.
Spitzer
The Spitzer is a very popular and aerodynamic bullet shape. This bullet is also called a spire point bullet by some people. The Spitzer has a BC modifier of 1.642 making it the 2nd best of the 5 in terms of it's ability to travel through time and space. There are also spitzer boattails...which gets a bit confusing in terms of generic BC values. If your bullet look like a sptizer but has a boattail (slanted end) then choose the Boattail from the form above.
[Back to Calculator]Boattail
The boattail is a modification to the rear end of a bullet making the projectile much more air resistent. It has a BC modifier of 1.965 and this number is for a Boattail Spitzer and not a Boattail hollow point. The Boattail hollow point has a much lower BC modifier of somewhere around 1.6
[Back to Calculator]Boattail Hollow Point
The boattail hollow point combines the airodynamics of the boattail with the expansion of the hollow point. It therefore has a lower BC modifier than the spitzer boattail, but a much higher modifier than the standard Hollow Point somewhere around 1.6
[Back to Calculator]Hollow Point
The hollow point has a small hollow cavity that expands to increase the surface area of the projectile on impact. It's hard to see from the picture above, but easier to see in pistol rounds. It has a BC modifier of .875 making it the least aerodynamic.
[Back to Calculator]RoundNose
The roundnose is a bullet that looks like it sounds...it has a round nose. It has a BC modifier of 1 and is the standard for our calculations. It is slightly more aerodynamic than the hollow point but worse than the spitzer and boattails. People often get caught up in new fads and forget about the roundnose. It is a classic round that has no frills attached, and is reliable and stable.
[Back to Calculator]Ballistic Coefficient Calculator: Understand Your Bullet's Aerodynamics
Our free online ballistic coefficient calculator helps you determine the BC of your bullets for more accurate shooting. Whether you're a hunter, competitive shooter, reloader, or firearms enthusiast, understanding your bullet's aerodynamic properties is essential for precision shooting.
This calculator allows you to calculate the ballistic coefficient based on bullet shape, weight, and diameter, giving you valuable insights into how your ammunition will perform in flight.
How to Use the Black Basin Ballistic Coefficient Calculator
- Enter Bullet Parameters - Fill in the bullet weight (in grains) and the bullet diameter (in inches).
- Select Bullet Shape - Choose from Spitzer, Boattail, Boattail Hollow Point, Hollow Point, or Roundnose bullet profiles.
- Calculate - Press the blue "Calculate" button to generate your ballistic coefficient.
- View Results - Review the calculated ballistic coefficient along with detailed information about the selected bullet profile.
- Use in Ballistics Calculator - Apply your calculated BC in our Ballistics Calculator for complete trajectory analysis.
Key Features of Our Ballistic Coefficient Calculator
Multiple Bullet Shape Support
Our calculator supports various bullet profiles including Spitzer, Boattail, Boattail Hollow Point, Hollow Point, and Roundnose, each with their unique aerodynamic properties.
Educational Content
Learn about the aerodynamic characteristics of each bullet shape and how they affect ballistic coefficient values and overall performance in flight.
Seamless Integration
Easily use your calculated BC value in our comprehensive Ballistics Calculator for complete trajectory, velocity, and energy analysis.
Understanding Ballistic Coefficient
What is Ballistic Coefficient?
Ballistic coefficient (BC) is a measure of a bullet's ability to overcome air resistance in flight. It's essentially a ratio comparing your bullet's performance to a standard projectile. Higher BC values indicate better aerodynamic efficiency, resulting in flatter trajectories, better wind resistance, and superior energy retention at distance.
Drag Models (G1 vs G7)
Ballistic coefficients are calculated against standardized drag models. The G1 model (used for most traditional bullets) is based on a flat-based projectile with a 2-caliber tangent ogive. The G7 model (better for modern boat-tailed bullets) is based on a boat-tailed projectile with a 10-caliber secant ogive. G7 BCs tend to be more consistent across different velocities for modern long-range bullets.
Factors Affecting BC
A bullet's ballistic coefficient is primarily influenced by its shape (more streamlined shapes have higher BCs), weight (heavier bullets typically have higher BCs), and diameter (smaller calibers tend to have less drag). Other factors include bullet construction, tip design, and surface finish.
Bullet Shape Characteristics
Spitzer
Spitzer bullets feature a pointed ogive (nose) that significantly reduces drag compared to older designs. This streamlined shape allows the bullet to maintain velocity better and results in flatter trajectories. Spitzer bullets typically have BC values around 0.4-0.5 for standard designs.
Boattail
The boattail design features a tapered base that reduces base drag. When combined with a spitzer nose, boattail bullets achieve excellent aerodynamic efficiency. These bullets excel at long range and typically have BC values ranging from 0.5-0.6 for standard designs.
Boattail Hollow Point
Combining the aerodynamic benefits of a boattail base with a hollow point tip, these bullets offer an excellent balance of ballistic performance and terminal effect. BCs typically range from 0.45-0.55, slightly lower than solid boattail bullets due to the hollow point.
Hollow Point
Featuring a cavity in the tip designed to promote expansion on impact, hollow point bullets sacrifice some aerodynamic efficiency for terminal performance. BCs for flat-based hollow points typically range from 0.3-0.4, depending on design specifics.
Roundnose
Traditional roundnose bullets have a hemispherical nose profile that produces significant drag. While less aerodynamically efficient than modern designs, they offer excellent reliability for certain applications. BC values typically range from 0.2-0.3, among the lowest of common bullet designs.
Practical Applications
- Long Range Shooting: Higher BC bullets maintain velocity and energy better at extended ranges, resulting in less drop and drift.
- Hunting: Understanding BC helps select ammunition that will deliver sufficient terminal energy at your expected shooting distances.
- Reloading: Calculate the BC of your hand-loaded bullets to predict performance and optimize loads for specific shooting applications.
- Competitive Shooting: Select the highest BC bullets appropriate for your discipline to minimize environmental effects on your shots.
- Ballistic Software: Use your calculated BC in ballistic apps and software for precise trajectory predictions.
Frequently Asked Questions
Are calculated BCs as accurate as manufacturer-provided BCs?
Calculated BCs provide a good approximation based on bullet geometry and physics, but manufacturer BCs are typically derived from actual testing. For the most precise ballistic calculations, use manufacturer-provided BCs when available. Our calculator is most useful for understanding relative performance between bullet shapes and for situations where manufacturer data is unavailable.
Why do BCs change with velocity?
Ballistic coefficients are not actually constant across all velocities. As a bullet slows, the relationship between its drag and that of the standard projectile can change. This effect is more pronounced with the G1 drag model than with G7. Manufacturers sometimes provide multiple BC values for different velocity ranges to account for this variation.
How does BC affect bullet drop and wind drift?
A higher BC means the bullet maintains velocity better, resulting in less drop over distance. More importantly, higher BC bullets are less affected by wind, sometimes dramatically so. For example, a bullet with a BC of 0.6 might drift half as much in a 10 mph crosswind at 500 yards compared to a bullet with a BC of 0.3.
Start Calculating Your Ballistic Coefficient
Enter your bullet specifications above, click calculate, and gain valuable insight into your ammunition's aerodynamic efficiency. Understanding your bullet's BC is the first step toward more precise shooting, whether at the range, in competition, or in the field.
Remember: While our calculator provides useful approximations, the most accurate BC values come directly from bullet manufacturers. When available, use manufacturer data for final ballistic calculations.