The meplat (from the

French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...

word "''méplat''" meaning "flat surface of a cylinder") is the technical term for the flat or open tip on the nose of a

bullet A bullet is a kinetic projectile, a component of firearm ammunition that is shot from a gun barrel. Bullets are made of a variety of materials, such as copper, lead, steel, polymer, rubber and even wax. Bullets are made in various shapes and co ...

. The shape of the meplat is important in determining how the bullet moves through the air. In particular the size and shape of the meplat has a significant effect on the

ballistic coefficient In ballistics, the ballistic coefficient (BC, ''C'') of a body is a measure of its ability to overcome air resistance in flight. It is inversely proportional to the negative acceleration: a high number indicates a low negative acceleration—the ...

of a bullet.

Theory

''Trimming'' the meplat (cutting the tip of the bullet, thus increasing its area) decreases the bullet's ballistic coefficient, increasing drag and making it more susceptible to wind drift. So even though the grouping will be tighter, the time of flight and wind drift will be slightly greater. ''Pointing'' the meplat (reducing its area) involves pressing the bullets into a special die. This decreases the size of the meplat which increases the ballistic coefficient and reduces drag, time of flight and wind drift. Some target shooters sort their bullets by weight, point their bullets and then trim them to the same meplat width to ensure the greatest possible consistency. Meplats are often used to increase the bullet's wounding ability. The shape of the nose of an axisymmetric projectile that gives it the least possible

aerodynamic drag In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding ...

hypersonic speed In aerodynamics, a hypersonic speed is one that exceeds 5 times the speed of sound, often stated as starting at speeds of Mach 5 and above. The precise Mach number at which a craft can be said to be flying at hypersonic speed varies, since indi ...

s always has a meplat, the diameter of which depends on the length of the nose.A.J. Eggers, Jr., Meyer M. Resnikoff, and David H. Dennis, "Bodies of Revolution Having Minimum Drag at High Supersonic Speeds", NACA Report 1306, 1955.

Varying meplats

If the meplats on a group of bullets are uneven, the trajectory of the bullets will vary which will cause the bullets to strike the target at different vertical locations. Bullets of the same mass that have similar-shaped meplats will travel through the air in nearly identical fashion, making it easier to group shots together or hit a

target Target may refer to: Physical items * Shooting target, used in marksmanship training and various shooting sports ** Bullseye (target), the goal one for which one aims in many of these sports ** Aiming point, in field artillery, fi ...

multiple times. For this reason, competitive shooters and

sniper A sniper is a military/paramilitary marksman who engages targets from positions of concealment or at distances exceeding the target's detection capabilities. Snipers generally have specialized training and are equipped with high-precision r ...

s often trim or point their meplats to uniform shape. Rounds of the same

caliber In guns, particularly firearms, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel bore – regardless of how or where the bore is measured and whether the finished bore matc ...

but with different-shaped meplats sometimes cannot be loaded into the same firearm. The meplat plays an important role in the loading of weapons whose ammunition is guided into the chamber by a mechanism (e.g.,

self-loading A semi-automatic firearm, also called a self-loading or autoloading firearm (fully automatic and selective fire firearms are also variations on self-loading firearms), is a repeating firearm whose action mechanism ''automatically'' loads a follow ...

pump-action Pump action or slide action is a repeating firearm action that is operated manually by moving a sliding handguard on the gun's forestock. When shooting, the sliding forend is pulled rearward to eject any expended cartridge and typically to co ...

lever-action The toggle-link action used in the iconic Winchester Model 1873 rifle, one of the most famous lever-action firearms Lever-action is a type of action for repeating firearms that uses a manually operated cocking handle located around the trigger g ...

, or

bolt-action Bolt-action is a type of manual firearm action that is operated by ''directly'' manipulating the bolt via a bolt handle, which is most commonly placed on the right-hand side of the weapon (as most users are right-handed). Most bolt-actio ...

firearms), though this usually is not important in weapons whose rounds are chambered by hand (e.g., single-shots, multiple-barrel firearms,

combination gun A combination gun is a firearm that usually comprises at least one rifled barrel and one smoothbore barrel, that is typically used with shot or some types of shotgun slug. Most have been break-action guns, although there have been other desi ...

s, or

revolver A revolver (also called a wheel gun) is a repeating firearm, repeating handgun that has at least one gun barrel, barrel and uses a revolving cylinder (firearms), cylinder containing multiple chamber (firearms), chambers (each holding a single ...

s.)

References

{{weapon-stub Ammunition

Theory

Varying meplats

See also

References