How To Make Primer Powder

Priming Compounds and Primers Introduction

Final Updated on Tue, 24 May 2022 | Ballistics

A priming compound is a highly sensitive explosive chemical which, when struck by the firing pin or hammer of a weapon, will explode with great violence, causing a flame to ignite the propellant.

This explosive chemical is oft mixed with other chemicals which provide oxygen to assist in the production of the flame, a fuel to increase the length and temperature of the flame and ground glass equally an abrasive to assist in the initial ignition of the explosive.

In the realms of forensic scientific discipline, the detection of primer discharge residuum on the hands tin provide crucial evidence as to whether a person has recently fired a weapon. To fully utilize the evidential value of gunshot remainder (GSR) analysis, a basic understanding of the history, composition and manufacture of primers is essential.

Primer Compound Recipe

Brusk history of priming compounds

The earliest priming compound was almost certainly mercury fulminate every bit used in the Forsythe scent canteen priming system which was introduced around 1806. This compound is highly sensitive and liable to spontaneously explode for no apparent reason. Every bit a consequence, the Forsythe smell bottle, which required a considerable quantity of this compound to exist carried in a container on the side of the pistol, did non achieve a cracking deal of popularity.

In 1807, Forsythe introduced a priming compound with a formula consisting of 70.six parts potassium chlorate, 17.6 parts sulfur and 11.viii parts of charcoal. Whilst this was somewhat more stable than mercury fulminate, it was terribly corrosive.

The starting time real percussion cap (a small metal loving cup containing the priming composition which was placed on a nipple at the rear of the barrel) was introduced past Joshua Shaw in 1814 and contained mercury animadvert. Every bit a result of the unpredictability of plain mercury fulminate, it was superseded in 1818 by a mixture of mercury fulminate, potassium chlorate, sulfur and charcoal. The residues produced past this mixture were, nonetheless, still terribly corrosive, requiring the weapon to be cleaned immediately after firing.

In 1828, Dreyse patented the 'needle gun ' , which had a paper cartridge case with the primer cup inside the instance with the propellant. The firing pivot on this weapon was a very long thin needle which penetrated the paper case hitting the primer within. This primer cup contained a mixture of potassium chlorate and antimony sulfide.

It was plant that purification of the mercury fulminate would pb to a more stable compound, and in 1873, a mixture of mercury fulminate, potassium chlorate, glass grit and gum arabic became the standard U.s.a. military priming compound. This mixture suffered from ii major drawbacks: (i) the mercury tended to make the contumely cartridge cases brittle, which led to case failure on firing and dangerous leakage of high-pressure gas from the breech of the weapon; and (2) the potassium chlorate left terribly corrosive residues in the bore of the weapon afterwards firing.

Non-mercuric, non-corrosive primer limerick

Every bit a result of these issues, the search began for a non-mercuric, non-corrosive primer limerick. Early attempts revolved around the employ of potassium chlorate as the main ingredient. Potassium chlorate is, however, a fairly unstable material and is very deliquescent, that is, it absorbs water from the atmosphere.

It as well forms potassium chloride on decomposition, which is also deliquescent and is very corrosive to the weapon'southward bore.

Merely prior to Globe War I, it was discovered that thiocyanate/chlorate mixtures were sensitive to impact. These, all the same, had the aforementioned drawbacks equally straight chlorate primers, that is, they produced corrosive residues on firing.

The German visitor RWS was the first to substitute the potassium chlorate with barium nitrate. Lead styphnate was used every bit the primary explosive component giving the offset 'rust free ' primer. This was patented in 1928 under the name Sinoxid.

The first true non-corrosive, non-mercuric (NCNM) primers were commercially produced in America between 1935 and 1938. These, yet, did not encounter the stringent United states of america government specifications as to storage, misfires, and so on, and military armament continued to use the erstwhile corrosive chlorate mixtures right through Globe War Ii.

In the United Kingdom, the change to non- corrosive armed services primers was even slower, and information technology was not until the early 1960s that all calibres in military and commercial primers used NCNM priming compounds.

Up to early 2000, the most common primer composition encountered was yet the atomic number 82 styphenate, barium nitrate, antimony sulfide and tetrazine type. In this priming compound, lead styphenate and tetrazine are the sensitive explosive ingredients; barium nitrate provides boosted oxygen to increase the temperature of the flame, and antimony sulfide acts every bit a fuel to prolong the burning time. Aluminium, and occasionally magnesium, can also exist encountered, but mainly in the college-powered magnum pistol or burglarize calibres.

Powdered glass was also oftentimes added to the mixture to increase the friction and to assist detonation when the mixture is crushed by the firing pin.

Modernistic 0.22" calibre rimfire ammunition is slightly unlike in that the limerick almost invariably consists of atomic number 82 styphenate, barium nitrate, tetra-zine and powdered glass.

Lead-free and not-toxic primers. It began to become apparent in the early 1970s that in heavily used training facilities, the range personnel were suffering from the symptoms of lead poisoning. Whilst a large proportion of this lead was beingness volatilized from the base of operations of the bullets, a portion was obviously coming from the lead styphenate primer.

The U.s. National Bureau of Standards claims that when lead-based primers are used, 80% of airborne atomic number 82 on firing ranges comes from the projectile and 20% comes from the priming composition. These percentages obviously depend on whether the bullet is plain lead or jacketed. In the case of a non- jacketed bullet, the rifling will strip atomic number 82 from the bullet' s surface, thus dramatically increasing the percent of non-primer-based airborne pb.

The change to a bullet with a copper/zinc jacket extending over the base of operations was a fairly simple matter of reducing the bullet sourced airborne lead, but finding a non-mercuric non-corrosive not-lead-based primer was another.

The problem was first solved in the early 1980s by Geco, who released a zinc- and titanium - based primer which they called " Sintox'. Since and so, there have been a number of other atomic number 82-complimentary primers produced by, for example, CCI Blazer, Speer, Federal and Winchester (Haag, 1995). The exact composition of the priming compounds used is non available, although SEM/EDX (scanning electron microscope/energy dispersive X-ray) analysis generally shows the presence of strontium in the Speer and Blazer cartridges, potassium in the Winchester cartridges and calcium and silicon in the Federal cartridges.

Most of the more recent primer formulations contain an initiator explosive compound called 'dinol', the chemic proper name of which is DDNP (diazodinitrophenol).

Other initiator explosives include:

dinitrodihydroxydiazobenzene table salt (diazinate);
dinitrobenzofuroxan salts;
potassium dinitrobenzofuroxan;
various diazo, triazole, and tetrazaole compounds;
perchlorate or nitrate salts of metal complexes of ammonium, amine or hydrazine an example of which is 2-(5-cyanotetrazolato)pentaaminecobalt III perchlorate (CP).

Oxidizers include:

zinc oxide
potassium nitrate
strontium nitrate
zinc peroxide

Fuel components include:

amorphous boron
metal powders, such as aluminium, zirconium, titanium, nickel and zinc
carbon
silicon
metal sulfides

Keep reading here: Zinc sulphide

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