| A | B |
|---|
| bore | the interrior of a firearm barrel |
| breechblock | rear part of a firearm barrel |
| caliber | diameter of the bore of a rifled firearm |
| choke | interior constriction placed at muzzle of shotgun to control shot dispersal |
| distance determination | determining the distance between firearm and target using distribution of powder patterns or spread of shot |
| ejector | mechanism that throws cartridge or fired case from firearm |
| extractor | mechanism that withdraws a cartridge or fired case from the chamber |
| firearms identfication | discipline concerned with determining whether a bullet or cartridge was fired by a particuar weapon |
| gauge | size designation of shotgun originally the number of balls with sam diameter of barrel that would make a pound |
| Greiss test | chemical test to show powder patterns around a bullet hole |
| grooves | cut or low-lying portions between lands in a rifled bore |
| lands | raised portions between grooves in a rifled bore |
| rifling | spiral grooves formed in the bore of a firearm that impart spin to projectile |
| twist | direction of lands and grooves imparted to a bullet as it moves down the rifled bore |
| button process | steel plug impressed with grooves is forced by high pressure through bore for rifling |
| broach process | concentric steel rings each larger than the other used rifle a bore |
| mandrel process | rod with reverse impression of grooves placed in bore then barrel is hammered to produce rifling |
| hook process | steel cutters individually cut each groove one at a time as it makes multiple passes down barrel |
| striations | fine microscopic scratches imparted to a bullet as it moves down a barrel |
| diphenylamine | reagent that turns blue in the presence of nitrates |
| dermal nitrate test | uses hot paraffin to capture nitrates from hand of suspect thought to have fired a gun |
| Sacco & Vanzetti | Goddard used comparison microscope to examine bullets used to convict these men in security guard murders |
| DRUGFIRE | FBI automated search system for cartridge casing markings |
| IBIS | BATFE database system with images of both expended bullets and cartridge cases |
| Bullet-proof | BATFE bullet analyzing program |
| Brasscatcher | BATFE cartridge case analyzing program |
| NIBIN | integration of IBIS and DRUGFIRE databases |
| bullet wipe | dark ring immediately around a bullet hole consisting of carbon, dirt, lubricant etc wiped off surface as it penetrates target |
