Priming compounds are extremely sensitive explosive chemical that, when struck by the firing pin or the hammer of a weapon will explode with great violence and cause a fire to ignite the propellant.

The explosive chemical is mixed with other chemical that supply oxygen in the development of the flame. These include fuel to boost flame length and temperature, as well as ground glass to act as an abrasive.

In the world of forensic science discovery of 209 primers’ discharge residues on hands could be a crucial indicator that a person has fired a weapon recently. To fully utilize the evidential significance of gunshot residue (GSR) analysis an knowledge of the history of the composition, manufacture and production of primers is vital. Visit article source for effective information 209 primers now.

The brief history of primer compounds

The first priming compound used was most likely mercury fulminate, as it was it was used in the Forsythe scent bottle priming system which was introduced around 1806. The compound is extremely sensitive and can explode without explanation. As a result, the scent bottle for Forsythe, which required a considerable quantity of this chemical to be carried in a container on the side of the pistol, failed to gain much recognition.

In 1807, Forsythe launched a priming compound with a formula consisting of 70.6 parts potassium chlorate, 17.6 parts sulfur, and 11.8 parts of charcoal. Whilst this was somewhat more durable than mercury fulminate, it was extremely damaging to the environment.

Joshua Shaw introduced the first cap for percussion in 1814. It was a small metal cup that contained priming mixture and was attached to a nipple on the rear of barrel. It was later replaced with a mixture of mercury, potassium chlorate and sulfur due to the instabilities of pure mercury fulminate. However, the residues from the mix were still highly destructive and demanded that the weapon be cleaned immediately after firing.

In 1828, Dreyse patented the ‘needle gun’, which had a paper cartridge case with the primer cup in the case, along with the propellant. The firing pin of this weapon was a thin, long needle that penetrated the paper case and hit the primer inside. This primer cup contained a mixture of potassium chlorate as well as antimony sulfide.

It was determined that removal of mercury fulminate could result in a more stable compound, and in 1873, a blend of mercury fulminate, potassium chlorate glass dust, and gum arabic became the standard US primeing compound for military use. The mixture had two main drawbacks: (i) the mercury tended to make the brass cartridge cases hard, which led to cases failing upon firing, and the risk of leakage of high-pressure gas out of the gun’s breech and (ii) the potassium chlorate caused destructive residues inside the bore of the gun after firing.

Non-mercuric, non-corrosive primer composition

In the wake of these challenges the search for a non-mercuric, non-corrosive primer composition. Initial attempts were based on potassium chlorate as the primary ingredient. Potassium chlorate, however, is a highly unstable material that absorbs water from the air.

When it decomposes, it creates potassium chloride. This is extremely destructive to the bore of a weapon.

It was discovered that blends of thiocyanate and chlorine were vulnerable to impact just before World War I. However, they came with the same disadvantages as straight chlorate 209 primers in that they produced corrosive residues on firing.

The German RWS company RWS was the first to substitute the potassium chlorate with barium Nitrate. Lead styphnate was used as the principal explosive component, providing the first “rust-free” primer. This invention was first patented under the name Sinoxid in 1928.

The first truly non-corrosive, non-mercuric (NCNM) primers were commercially manufactured in America between 1935 and 1938. These, however, did not meet the stringent US government requirements regarding storage, misfires and so on, and military ammunition used traditional corrosive chlorate mix right up to World War II.