This brings the cartridge into the mix, and possibly a trade-off in muzzle velocity for heavier bullets. So, in this case, the quarter has a very low sectional density because its mass is divided by a large number that represents its surface area. One more thing. Spitzer, which means pointed, is a more efficient shape than a round nose or a flat point. As for distances, I'd already decided to choose 50 yards as the close mark, and after some discussion the editor settled on a max of 400 yards- a long shot, for sure, but a range at which most accomplished riflemen can make clean, ethical hits from field positions. Ballistic Coefficient values at Mach 1.75 (1954 fps @ ICAO Standard Atmosphere), should be used when calculating trajectories for shooting beyond 600 yds. Mag., .308 Win, .30-06, .300 Win. Succinct explanations for someone just getting started. If we change the density of what the two objects are traveling through, the less-efficient tennis ball will be affected by the change more. But the more streamlined bullets have a higher ballistic coefficient. It details drop, time, energy, velocity, range, and does so in . A bullet's BC will differ depending on whether the G1 or G7 drag model is used. The more efficient a bullet is, the better it will maintain its speed. The fastest, most streamlined bullet may go right thru the animal you're shooting at, so you might need to use a heavier bullet that doesn't move as fast, but expands a lot more & won't go all the way thru. The first thing to note is that not all bullet manufacturers measure their BCs in the same way. The __gads cookie, set by Google, is stored under DoubleClick domain and tracks the number of times users see an advert, measures the success of the campaign and calculates its revenue. Or killing a deer with one shot. A slower barrel twist of 1:10 is generally adequate to stabilize bullets weighing up to 100 grains, while the accuracy of heavier, higher ballistic coefficient bullets is improved by a 1:7 or 1:8 twist. is both capable and popular, especially on the heavy-bodied game where bullet performance becomes critical. For example, your bullet doesnt fall more at farther distances because of the distance (the bullet doesnt know how far it is traveling), but rather because it takes longer to reach a farther target, and therefore it has more time to fall due to gravity. As Hornady moves the industry to drag coefficient based trajectory calculations for these types of projectiles, the Ballistic Coefficient is becoming somewhat irrelevant. There is a pretty big difference in trajectory between the round nose bullet and the two pointed bullets, making it obvious why it is folly to choose a round nose bullet for long range shooting with a high velocity rifle like a 6mm Remington or .243 Winchester. 10 Best 6.5mm Rifle Cartridges Available Right Now An interesting subject, this ballistic coefficient, and worth paying attention to when you select a bullet (or a caliber) for long range shooting. Until now. This is because the value for the shape of the bullet is determined by how close its shape is to the drag model. Save my name and email to use for future comments. All three of these bullets have a sectional density (which is the ratio of a bullet's diameter to its weight) of .242, because they are all .243" in diameter and weigh 100 grains. My next preferences is Sierra, Swift and Hornady. A particular bullet will have a different BC depending on whether the G1 or G7 drag model is used. When it comes to hunting or defensive use, you need the bullet to be in a certain velocity range to ensure the expansion of the projectile when it hits a target. And they come in two varieties: Those designed for hunting, and those designed for target shooting. The BC of a bullet is a ratio calculated by a mathematical model based off of its density and its particular shape. Very short and wide. 5 Mk 1 Rifle: History of the 'Jungle Carbine', Kimber Hunter Pro Desolve Blak - A Lightweight Heavy Hitter, Browning BLR Lightweight '81 Stainless Takedown Lever Rifle, Mossberg Patriot Predator 6.5 PRC Rifle Review, Review: Springfield Armory M1A Loaded Rifle in 6.5 Creedmoor, RCBS ChargeMaster Lite Review: Not 'Lite' on Ability, Remington Model Seven SS HS Bolt-Action Rifle Review. BC is what determines trajectory and wind drift, other factors (velocity among them) being equal. Mag. These bullets have extremely high BCs. Both can be launched at the same speed, but an arrow will fly farther because it doesnt slow down as much due to wind resistance and therefore maintains its speed better. bullets). There are three variables that determine a bullets speed on its way to the target: We explored the first variable, the initial speed of the bullet, in the last column. Conversely, it's not that difficult to produce a bullet that will hold together at close-range, high-impact velocities, but the heavy jackets, harder lead-alloy cores and bonding processes used to create such bullets can inhibit expansion when distances stretch and velocities drop. They typically expand violently, causing tremendous wound cavities and resulting in rapid kills. google_ad_client = "ca-pub-8417283882784443"; It delivers smaller BCs but is consistent throughout the velocity of the round, giving you a much more accurate representation of BC. There are actually several different standard projectiles with different measurements and they each measure drag in a different way. A decent BC for a bullet based on the G1 drag model is in the 0.5-0.6 range, whereas the same bullets BC based on the G7 drag model will be in the 0.2-0.3 range. Instead search for the bullet on the top left using the search box or browse by rifle, or pistol using the links from the main menu. In this comparison, the 6.5mm 144 gr bullet has a G7 BC of 0.336, while the 30 cal 175 grain OTM has a G7 BC of 0.263. Comparing Ballistic Coefficients (BCs) | Berger Bullets Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. It does not store any personal data. Quantserve sets the mc cookie to anonymously track user behaviour on the website. In each pair, the first bullet has a flat base, and the second has a boat tail. Learn more . Learn more about our new Long Range Hybrid Target bullets. In actuality, the smaller caliber, lighter-weight bullet actually has a BC thats 28% higher than the larger caliber, heavier bullet. Conversely, if we launched the two objects in a vacuum (no air resistance), then both would continue to fly at the same speed. Thanks! The other is a 150-grain Sierra Matchking. Now, lets launch them both at 2,750 feet per second from a Sierra Bullet Blaster 7000 rifle and see what happens. Articles may contain affiliate links which enable us to share in the revenue of any purchases made. Don't be confused the next time you hear "ballistic coefficient" tossed around by long-range shooters. That boils down to more complex factors like shape, length, and weight distribution. Notify me of follow-up comments by email. The definition according to Wikipedia is, the ballistic coefficient (BC) of a body is a measure of its ability to overcome air resistance in flight.. If more than one bullet shoots equally well, then choose the one with the higher BC. In actuality, the smaller caliber, lighter-weight bullet actually has a BC that's 28% higher than the larger caliber, heavier bullet. Lets assume youre shooting a .308 rifle and you have two types of bullets of identical weight. The U.S. Army calls the round "next generation," and based on .277 Fury's capabilities, that is not an exaggeration. Correct? The nail flying point forward has a very high sectional density because its long and skinny. However, the science and scientists that got us to this point goes back all the way to the 16th century. This difference in the two BCs for the same bullet is because an efficient bullets performance will be much better than the G1 model and only slightly better than the G7 model. The slower the bullet the less range youll have. The G1 drag model is based off of a stereotypical spitzer bullet (pointed nose) with a flat base. There are just so many factors to consider, many of which the manufacturer cant know, including atmospheric conditions, the drag created by your rifling, and more. These two bullets, while of the same weight, have different ballistic coefficients. I dont see how a BC can be constant for varible velocities over a given trajectory. Ballistic Coefficient (BC) is basically a measure of how streamlined a bullet is; that is, how well it cuts through the air. And the .300 Win. How to Sight in a Scope - Step by Step Guide. The longer they have to act on your projectile, the more of an effect theyll have. Get proficient on YOUR time. Lets design a standard bullet and do all the math for that one. Ballistic Coefficient: 0.14 Bullet Weight: 115 gr Initial Velocity: 1100 fps . Kimber's Hunter Pro Desolve Blak takes the firm's more affordable mountain rifle to new heights. These bullets will withstand high-velocity impact at close range and still deliver expansion at distances to and beyond 800 yards. The pattern element in the name contains the unique identity number of the account or website it relates to. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. This system is a great way to compare cartridge systems so you can better make an informed purchase. Knowing ballistic coefficient allows you to calculate how far your round flies as it loses velocity. Originally, those smart people who did a lot of testing on the range worked out predictive models for bullet flight based on that standard projectile shape. YouTube sets this cookie via embedded youtube-videos and registers anonymous statistical data. He is interested in helping folks protect themselves with firearms and shoot better at the range. Another thing to keep in mind when comparing BCs is related to caliber. Thats where it started, and since then its gone from simple experiments all the way to engineers and scientists at places like Aberdeen Proving Ground working to improve ballistic calculations. One is a 150-grain Sierra Pro-Hunter. Ballistics is an odd, but fascinating science, and it can be intimidating to go too deep. Some of the links on this page are affiliate links, meaning at no additional cost to you, Ammoland will earn a commission if you click through and make a purchase. This will support more accurate trajectory predictions, including wind and drop predictions. Set by the GDPR Cookie Consent plugin, this cookie is used to record the user consent for the cookies in the "Advertisement" category . Select what level shooter you are! His books are available in print and eBook format on Amazon. These bullets also feed very well from the detachable magazines being used by most long-range semi-auto and bolt-action rifles. The cookie stores information anonymously and assigns a randomly generated number to recognize unique visitors. Bullet Ballistics & Charts GunData.org The belted cartridge can be loaded for velocities up to 3,500 fps with lighter bullets, but the best long-range loads use a heavier bullet with a higher BC and velocities between . google_ad_slot = "7610963244"; The cookie is used to store the user consent for the cookies in the category "Performance". Travis Pike is a Marine infantry veteran, firearms enthusiast, and NRA certified instructor. The ELD-X (Extremely Low Drag - eXpanding) bullet is a technologically advanced, match accurate, ALL-RANGE hunting bullet featuring highest-in-class ballistic coefficients and consistent, controlled expansion at ALL practical hunting distances. If looking to acquire an automated powder-charge dispensing unit to speed up precision reloading, don't judge the RCBS ChargeMaster Lite powder scale and dispenser by its name; the Little Green machine packs a heavy-weight punch with speed and accuracy. When using 90-grain bullets with a very high ballistic coefficient at .563 G1 BC, the 224 Valkyrie is a legitimate three-quarter-mile cartridge. Much of your article is reinforcement of what I have gathered previously in several different articles. If a Mach number is unavailable, velocity can be used if the BCs are corrected to Standard Atmosphere which is fairly typical practice within the industry. We'll send you the latest guides and training tips geared google_ad_height = 90; This cookie is set by GDPR Cookie Consent plugin. Sectional density is easy to calculate because it simply depends on the bullets caliber and weight. In this case, the Form Factor becomes 1.0 and the BC equals the Section Density.Read more , This But that one- mile-plus first shot GONG is addictive!!! I didnt know, but the term came up enough in forums, articles, and videos that I had to do some research. My best "take away" was the reinforcement of consistency in long range shooting. Bullets that are too heavy can drop sharply because of an increased rate of drag. Punching holes in a target? Thats because the BC varies with speed. Weve built dozens of ARs and well cover all the best AR-15 upgrades such as handguards, triggers, BCGs, gas blocks, and more. . This cookie is set by GDPR Cookie Consent plugin. With the right BC you can make a . The new Tipped MatchKing is living up to that legacy. Using B.C. It wasn't hard to choose a bullet diameter and weight and a cartridge through which to test it: America is still a .30 caliber nation; 180-grain projectiles typically offer excellent sectional density and ballistic efficiency; and the .300 Win. It scored just behind the .340 Weatherby and has the least recoil among the cartridges tested. Its currently available in loaded ammunition and as a component for handloaders in .277, .284, and .308 calibers.