Muzzle residue

Table 25.2 Membrane Pore Size Experiment on Muzzle Residue...

Mice that were exposed dermally to residues of methyl parathion in emulsifiable concentrate on foliage, and were muzzled to prevent oral intake, developed inhibition of plasma cholinesterase and erythrocyte cholinesterase after two 10-hour exposures (Skinner and Kilgore 1982b). For the organophosphate pesticides tested in this study, cholinergic signs generally were seen in mice with cholinesterase inhibition >50% results for this end point were not broken down by pesticide. 

A high ballistic efficiency can be obtained by burning the propellant charge as early as possible in the projectile s traverse of the gun bore thereby reducing residual muzzle pressure. 

Numerous terrorist activities as well as many serious criminal offensives involve firearms. When a firearm is discharged, a variety of materials is emitted by the muzzle (accompanying the projectile), including primer and gunpowder (propellant) residues... 

When a round of ammunition is discharged in a firearm, in addition to the projectile(s), firearm discharge residue is emitted, mainly from the muzzle but also from cylinder gaps, ejection ports, and other vents in the firearm. Some of this residue may be deposited on the skin, head hair, and clothing of the firer. 

It was also observed that the number of discharge residue particles on the firing hand decreased markedly as the bullet velocity increased. One possible explanation for this is that the greatly increased suction in the wake of the faster bullet causes more particles to be sucked out of the muzzle leaving fewer to exit from other vents and to be deposited on the hand. This... 

There is evidence to suggest that the FDR on the firer s hand is blasted on to the hand during the firing process and that residue settling from the atmosphere does not appear to contribute. Copious amounts of FDR issue from the muzzle but play a secondary role in hand deposits. The hand deposits are mainly emitted from openings around the breech and ejection port in self loading firearms and from the flash gap between the cylinder and barrel in revolvers.174 Such residues can also be deposited on to the face, head hair, and clothing of the firer. 

Firing location and duration of exposure—Firing from confined spaces, for example, doorways, small rooms, vehicle interiors, will tend to expose the firer to a more residue-laden environment for a longer than normal period of time consequently, it will take the FDR longer to disperse and the chances of FDR from the muzzle being deposited are increased. 

This test involved the discharge of a complete round of ammunition and facilitated the examination of discharge residue exiting the muzzle of the firearm. The primary objective of the examination was to determine what... 

The proportion of the discharge residue issuing from the muzzle that has the potential to be detectable by SEM is 12.1%, 11.7%, and 13.5%, respectively. These figures are remarkably reproducible given the scope for experimental error in this type of experiment. The distribution between the filter and the liquid traps, that is, between particulate and vapor, is 17.7%, 17.2%, and 20.2%, respectively, on the filter. 

Table 22.10 Mercury Levels in Muzzle Discharge Residue...

The primer chemicals are not alone in toxic compound deposition however. Microscopic lead and copper particles are also scraped off the bullet as it races through the gun barrel, and are propelled out the muzzle by the force of the burning powder. RSI (Recreational Software, Inc.) notes all barrels and all ammos foul and that copper residue especially, from copper jacketed rounds, is cumulative. Fouling accumulates and tears at the base of a bullet jacket, scarring it as it rushes down the barrel, and the more you shoot, the more dust and fouling is left inside the gun and blown into the air. 

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