Posted by: episystechpubs | March 12, 2020

Editor’s Corner: Lands and Grooves

One of my guilty pleasures is watching crime shows. Law and Order of any flavor (SVU, Criminal Intent, etc.), Blue Bloods, Forensic Files, and several British crime shows. This year, Forensic Files II is here, and I am giddy as I watch each week!

As I was catching up on the Forensic Files of the past, one of the scientists was talking about the striations on the bullet caused by the “lands and grooves.” Although I’d heard this term so many times, for some reason this time it sounded a little odd to me. Lands? What the heck? So today, I am doing a nod to Forensic Files, and delving a bit into gun vocabulary.

Some of you may love guns, some of you may hate them. I’m not here to judge, I’m just here to talk about the language. Here are just a few of the terms I found (in alphabetical order):

Ballistics: The study of a projectile in motion. Often confused with Firearms Identification, there are three types of ballistics: Interior–within the firearm, Exterior–after the projectile leaves the barrel, and Terminal–impact on a target.

Bore: The inside of the barrel. "Smoothbore" weapons (typically shotguns) have no rifling. Most handguns and rifles have "rifling.”

Forensic: Okay, so I added this to the list. Here is the definition and the etymology.

  • Forensic (adj.) relating to or denoting the application of scientific methods and techniques to the investigation of crime.
  • forensic (adj.) "pertaining to or suitable for courts of law," 1650s, with -ic + stem of Latin forensis "of a forum, place of assembly," related to forum "public place.” Later used especially in sense of "pertaining to legal trials," as in forensic medicine (1845).

Griess test: A chemical test for the detection of nitrites. It is used to develop patterns of gunpowder residues (nitrites) around bullet holes.

Lands and grooves: Rifling. Lands are the raised portions between the grooves inside the barrel after the spiral grooves are cut to produce the rifling.

Rifling: The spiral grooves cut or swaged inside a gun barrel that gives the bullet a spinning motion. The metal between the grooves is called a "land." The spiral can have either a left or right twist.

Striation: A set of parallel surface contours (scratches or scrapes) on an object caused by a combination of force and motion.

Have a safe day, without the need for any forensic specialists.

Kara Church

Technical Editor, Advisory

Symitar Documentation Services


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Categories

%d bloggers like this: