thumb|right|An assortment of .30-caliber (7.62 mm) round-nose bullets illustrating the exposed lead tip characteristic of soft-point bullets.
right|thumb|Some soft point bullets have a more [[Aerodynamics|aerodynamic contour like these spitzer boat-tail bullets]]
A soft-point bullet (SP), also known as a soft-nosed bullet, is a jacketed expanding bullet with a soft metal core enclosed by a stronger metal jacket left open at the forward tip. A soft-point bullet is intended to expand upon striking flesh to cause a wound diameter greater than the bullet diameter. Jacketed soft point bullets are usually abbreviated JSP in the ammunition and reloading industry. The use of soft-point bullets in warfare is a violation of the Hague Convention of 1899, declaration IV, 3.
Evolution
Lead-alloy bullets used with gunpowder firearms were unsatisfactory at the bullet velocities available from rifles loaded with nitrocellulose propellants such as cordite. By the late 19th century, lead-alloy bullets were being enclosed within a jacket of stronger mild steel or copper alloyed with nickel or zinc to reliably impart stabilizing rotation in rifled barrels. The lead-alloy core was swaged into a cup of the stronger metal covering the front and sides of the core, but leaving some of the core exposed on the base of the bullet. The bullet jacket may be described as a metal envelope, steel envelope, or hard envelope; and the jacketed bullet may be described as metal-covered, metal-patched, or metal-cased.
But while these new types of projectile were easier to stabilize at the new high velocities, it was discovered that the new jacketed design was actually less lethal than the softer lead-alloy types that had preceded it.
The jacketed bullets were typically of smaller diameter than the previous lead-alloy type, and the stronger jacket made them less likely to be deformed on impact. Such deformation increases the effective diameter of the projectile and can also cause an erratic trajectory within the wound. Enclosing the lead or alloy within a hard jacket cuts down on these tendencies despite the greater velocities employed, and this in conjunction with the typically smaller calibre created a greater tendency for the new rifle bullets both to create a smaller wound and to pass through, rather than lodging within, the anatomy of the target whether human or animal, thus increasing the probability of wounding rather than killing. For this reason, full metal jacket rounds are considered more humane for military purposes; conversely, they are less effective for hunting animals where killing the quarry swiftly is the objective. To produce a smokeless-propellant round that would engage in rifling efficiently but also match or exceed the lethality of the old, low-velocity ammunition it was necessary to invent the soft-point. The process was not difficult: reversing the direction of jacket placement leaves the lead-alloy core exposed at the forward tip of the projectile creating a soft-point bullet. newer bullet designs with polymer tips offering improved ballistics have become available for safe use in tubular magazine rifles.
See also
- List of firearms
- List of rifle cartridges
- List of handgun cartridges