Patent Application
20190107372
In the anatomy of a bullet, the meplat is a small flat area at the outer tip of the head of the bullet. Many rifle rounds implement a meplat. In the case of copper-jacketed rounds, a meplat may form as a side effect of the manufacturing process, when molten lead is injected into the copper jacket. With respect to solid, single material (i.e., monolithic) bullets, the tip of the bullet may be deliberately cut to a particular diameter. Generally, from an aerodynamic perspective, the smaller the meplat of the bullet, the better the bullet performs aerodynamically. However, as the meplat decreases in size, the difficulty in manufacturing increases.
Conventionally, several different bullet tip meplat designs are used, including: a small round tip, an infinitesimally sharp (pointed) tip, and a tip having an aggressive downslope close to the tip. Each of the conventional designs suffer from various flaws, such as difficulty in the manufacturing process which leads to inconsistency in production for consistent reliable performance.
The small round tip is very difficult manufacture it correctly. Frequently, slight changes in tooling will have significant effects on the geometry of the tip. In addition, extensive testing shows that when firing rounds with the small round tip meplat design, the shot placement accuracy tends to be less than for rounds having a simple meplat.
Even more challenging to manufacture than the small round tip meplat is an infinitesimally sharp (pointed) tip meplat. This tip design suffers from the same accuracy issues described above with respect to the small round tip meplat. In addition, due to the minimized strength of the tip inherent in the material when reduced to such a small shape, the tips are prone to damage caused by collisional movements, such as may occur during the loading operation of the round to a firearm's chamber when shooting. This damage, in the form of flattened and/or bent tips may affect consistency in placement accuracy as well.
While the meplat of an aggressive downslope close to the tip allows for a heavier, thicker cone, this design creates extra pressure at the tip. Moreover, this tip design also suffers from the same accuracy issues described above.
Thus, compared with and in view of the above concerns with other meplat designs, a simple meplat may be easier to manufacture and may provide for more consistent shot placement accuracy and reliability when fired.
The Detailed Description is set forth with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items. Furthermore, the drawings may be considered as providing an approximate depiction of the relative sizes of the individual components within individual figures. However, the drawings are not to scale, and the relative sizes of the individual components, both within individual figures and between the different figures, may vary from what is depicted. In particular, some of the figures may depict components as a certain size or shape, while other figures may depict the same components on a larger scale or differently shaped for the sake of clarity.
This disclosure is directed to an improved meplat tip design for decreasing pressure build-up and thus turbulence on a projectile. That is, consistent with the title of this disclosure, it is contemplated that other types of projectiles beyond bullets may employ a meplat as disclosed herein.
In an example projectile, the implementation of the meplat described herein, is described with respect to improving consistency and accuracy of a fired bullet. At least one of the following advantages may be achieved with the implementation on a projectile of a meplat according to an embodiment of the instant disclosure. For example, advantages of a bullet having a meplat according to an embodiment of the instant disclosure compared to bullets having conventional meplats (e.g., bullets with a small rounded meplat, an infinitesimally sharp (pointed) tip meplat, a meplat of an aggressive downslope close to the tip, etc.) may include: easier manufacturing; superior aerodynamic performance; increased durability; improved loading capability; etc., each of which assist in superior shot placement accuracy, when the meplat is discussed in terms of a bullet as the projectile.
Specifically,
In bullets having a small to medium sized rifle caliber, (e.g., .223, 300BLK, .308Win, etc.), flat portion 200 may have a diameter dimension (i.e., equal to 2*r) of about 0.4 mm. In an embodiment, the diameter dimension of flat portion 200 may range from about 0.35 mm to about 0.45 mm. Using a chamfer angle “a” ranging from about 51 degrees to about 53 degrees (based on the caliber and the ogive), such as, for example, 52.5 degrees, a chamfer depth “d” may be about 0.1 mm.
In larger caliber rifle bullets (e.g., .338, 50cal, etc.), an embodiment of the flat portion 200 may have a diameter (2*r) that ranges from about 0.4 mm to about 0.7 mm. Further, for the larger caliber rifle bullets, the chamfer depth d may range from about 0.1 mm to about 0.3 mm, for example.
Turning to the results shown in the images of
Accordingly, a projectile implementing a meplat according to the instant disclosure may have significant advantages including superior aerodynamic performance.
Although several embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that the claims are not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the claimed subject matter.
This application claims priority to U.S. Provisional Patent Application No. 62/569,383, filed Oct. 6, 2017, the content of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62569383 | Oct 2017 | US |
