Bullet jackets materials

The bullet jacket material is almost always harder than the bullet core material, with the one exception of armor-piercing bullet jackets. Bullet jacketing is done either by electroplating or, much more commonly, the jacket is manufactured separately from the bullet, and the bullet then forced into the jacket in a press. Another method is to pour molten lead into the jacket. The edges of the jacket are usually partly rolled over the base of the bullet or attached by some other physical means. 

Bullet jacket materials include gilding metal cupronickel cupronickel-coated steel nickel zinc-, chromium-, or copper-coated steel lacquered steel brass nickel- or chromium-plated brass copper bronze aluminum/alumi-num alloy Nylon (Nyclad), Teflon- and cadmium-coated steel (rare). Black Talon bullets have a black molybdenum disulfide coating over the metal bullet jacket which acts as a dry lubricant. Steel jackets are frequently coated both inside and outside as an anticorrosion measure. Gilding metal is by far the most common bullet jacket material. Tin is claimed to have lubricating properties and is sometimes incorporated in bullet jacket material. The alloy is known as Lubaloy or Nobaloy and contains 90% copper, 8% zinc, and 2% tin. 

Tests were also conducted to determine if it was possible to identify the bullet jacket material from examination of the bullet hole perimeter. The ammunition used is given in Table 20.12 and the test results are presented in Table 20.13. 

Overall, the possibility of determining the bullet jacket material from the residue around the bullet hole does not appear to be feasible using FAAS. However, FAAS reliably detects elements associated with firearm discharge on the perimeter of the bullet hole and is a very useful method for confirming bullet damage. 

A bullet jacket is normally harder than the bullet core material but soft enough to take up the rifling and not cause excessive wear to the barrel. Bullet jackets were for a long period made of cupronickel (80% copper, 20% nickel), gilding metal (90% to 95% copper, 10% to 5% zinc) or steel which was coated... 

Sometimes a combination of bullet core materials is used to produce a hardness difference between the base and the nose (dual core bullets), for example, jacketed bullets with a lead nose and a steel base, a steel nose and a lead base, or a soft lead nose and a hardened lead base. 

Detailed analysis of the perimeter residue often yields useful information, for example, whether the bullet is unjacketed or jacketed and the nature of the jacket material. Primer type may occasionally be inferred and the presence of strontium or magnesium indicates a tracer or incendiary bullet, respectively. 

Copper alloy bullet jackets are by far the most common and coated iron jackets are also frequently employed. Lead is by far the most common bullet core material and is often hardened with antimony, but not as often as originally presumed, with antimony occurring in only 25% of the lead bullets examined. Only one of the bullets examined was hardened by tin. Some... 

Bullets and shot are usually lead or lead-antimony alloys of between 0.5% and 3% antimony to harden the lead (in rare cases tin can be the hardener). Bullets can also be semijacketed, tipped, or fully jacketed, with copper and copper alloys with zinc and/or tin being the most common materials. Bullet jackets... 

Speer loads Lawman Clean-Fire with Speer TMJ. The lead core is completely and seamlessly encased in jacket material so powder gases can t burn lead off the bullet base. This design is superior to other base cap bullets where the caps can loosen, leaking lead and destroying accuracy. 

The principal military use of brass was formerly for the manuf of cartridge cases (See Vol 2, pC78-R), but now other materials are used, such as steel, plastics and colloided smokeless proplnts. Another Cu alloy, bronze (Cu 90 Sn 10%) was formerly used for casting gun barrels (Ref 13, p 167), but now steel is used for that purpose. The so-called gilding metal (Cu 90 Zn 10%) has been used as a jacket for lead-alloy bullets (See Vol 2, p B327-R, under Bullets, Metal Jacketed)... 

The core of the bullet can be made from a variety of materials lead is by far the most common because of its high density and the fact that it is cheap, readily obtained, and easy to fabricate. But copper, brass, bronze, aluminum, steel (sometimes hardened by heat treatment), depleted uranium, zinc, iron, tungsten, rubber, and various plastics may also be encountered. (When most of the fissile radioactive isotopes of uranium are removed from natural uranium, the residue is called depleted uranium. Depleted uranium is 67% denser than lead, and it is an ideal bullet material and is very effective in an armor-piercing role, both in small arms and larger munitions components. Because of its residual radioactivity its use is controversial.) Bullets with a lead core and a copper alloy jacket are by far the most common. 

Some jacketed bullets incorporate a small cavity in the nose which is filled with a material different from the bullet core. In some bullets the cavity... 

Detectable FDR is mostly particulate in nature. Unjacketed lead bullets produce residue in which greater than 70% of the particles are lead. Coated bullets give the same result, except that a substantial proportion of the lead particles contain copper from the coating material. With jacketed or semi-jacketed bullets the proportion of lead particles in the residue is greatly reduced. It was concluded that most of the lead in the residue comes from the bullet rather than from the primer. This has subsequently been confirmed by experiments involving the use of radioactive tracers.172... 

Bullet performance drives Barnes designs. Whether a Barnes bullet contains a lead core or not depends on the desired terminal performance. We have several lines of products manufactured from lead-free materials that were developed for their performance. These happen to meet the criteria set forth under the Condor Preservation Act, but we still manufacture the premium Original line of jacketed, lead-cored bullets. A lead ban would remove the very foundation on which our company was built. 

MRX - Barnes calls the ultra-dense lead-free core of this copper-jacketed green rifle bullet Silvex. It is a tungsten matrix material and rings cut into the bearing surface of the bullet increase accuracy and reduce fouling. ... 

SinterFire bullets are full-bodied one-piece designs with no jacketing, plating or surface treatment. Materials are 100 percent certihed, fully traceable (by paper trail) and virgin, meaning there is no chance that extraneous recycled materials will be inside a bullet to reduce its performance. That way, Benini says, the company can control the fragmentation properties of the projectile upon impact with hard surfaces. Bullets literally crumble to dust on impact with surfaces harder than themselves. 

---