Precision Rifle Glossary

Action

Also called: inlet

The mechanical heart of the rifle that loads, fires, and ejects cartridges. Think of it as the engine of your gun.

ARCA

Also called: arca swiss, arca-swiss

A standard rail system on the bottom of a rifle for quickly attaching bipods and tripods. It works just like a camera tripod quick-release plate.

Bolt Face

The front part of the bolt that pushes against the back of the bullet. It's like the palm of a hand pushing the bullet into the chamber.

Bolt Lift

The upward movement required to unlock the bolt before pulling it back. It's like lifting the latch on a gate before you can swing it open.

Bolt Throw

The distance the bolt handle travels when you cycle it. It's like the difference between a short-throw sports shifter and a long truck shifter.

Bullet Drop

How far the bullet falls toward the ground due to gravity as it travels. It's the arc of a thrown baseball as it loses speed.

Cant

Also called: canted

Tilting the rifle to the left or right instead of holding it perfectly level. It's like holding a camera slightly crooked when taking a picture.

COAL

Also called: C.O.A.L, Cartridge Overall Length

The total length of a fully assembled bullet from the tip to the flat base. It's the bumper-to-bumper measurement of your ammunition.

Cold Bore

The state of a rifle barrel before any shots have been fired to heat it up. Think starting a car engine on a freezing winter morning.

DBM

Also called: detachable box magazine

Detachable Box Magazine. A bottom-metal system that lets you drop a magazine and swap in a loaded one, instead of feeding rounds one at a time from the top.

DOPE

Also called: Data On Previous Engagements, D.O.P.E., D.O.P.E

Your personal record of how much your bullet drops at various distances. It's the customized cheat code for hitting targets with your specific rifle.

DSSF

Also called: Double Stack Single Feed, D.S.S.F, D.S.S.F.

A magazine where bullets sit side-by-side but merge into a single line at the top. It's like a two-lane highway merging into a single lane. It allows for a shorter magazine height with the same round count.

Ejector

A small spring-loaded pin that forcefully kicks the empty casing out of the rifle. Think of it as a tiny kicker that boots the empty shell out the door.

ELR

Also called: Extreme Long Range, E.L.R, E.L.R.

Shooting at targets that are a mile or more away. It's the extreme marathon distance of the precision shooting world.

Eye Relief

The perfect distance your eye needs to be from the scope to see a clear picture. It's the sweet spot for viewing, like sitting the perfect distance from a movie screen.

FFP

Also called: First Focal Plane

A scope where the crosshairs grow and shrink as you zoom in and out. It's like drawing a grid on a photo before you enlarge it; the grid scales perfectly with the image.

Free Float

Also called: Free-Floating, Free floating, free floated

When the barrel is attached only to the action and doesn't touch the stock anywhere else. It's like a diving board attached only at one end (your action) so it can vibrate naturally.

Holdover

Aiming your crosshairs slightly above the target to account for bullet drop at long range. It's like aiming a basketball slightly higher to make a long three-pointer.

LOP

Also called: length of pull, L.O.P, (LOP)

Length of Pull. The distance from the trigger to the back of the buttstock. Getting LOP right makes the rifle fit your body so your head and eye land in the same place every shot.

M-16 extractor

An M-16 extractor is a robust, heavy-duty claw-style component modeled after the AR-15/M16 rifle bolt system.

MIL

Also called: Milliradian, MILRAD

A unit of measurement in scopes used to calculate bullet drop and wind drift. Think of it as a metric ruler built into your crosshairs.

MOA

Also called: Minute of Angle, Minutes of angle

A common measurement in scopes where one unit equals about one inch at 100 yards. It's the standard inch-based ruler used by American shooters to adjust their aim.

NPA

Also called: NPA

Where the rifle naturally points when your body is completely relaxed. It's the resting heartbeat of your shooting stance.

Parallax

An optical illusion where the crosshairs seem to float off the target if you move your head. It's like looking at a speedometer from the passenger seat—the needle looks like it's pointing to the wrong number.

POA

Also called: Point of Aim

The exact spot your crosshairs are resting on before you pull the trigger. It's where you are looking, not necessarily where the bullet will go.

POI

Also called: Point of Impact

The exact spot where the bullet actually hits the target. It's the final destination of the bullet, which changes with wind and distance.

Pull Weight

Also called: Trigger Pull Weight

The exact amount of pressure your finger needs to apply to make the gun fire. It's how heavy or light the 'click' of the mouse feels.

SFP

Also called: Second Focal Plane, 2FP

A scope where the crosshairs stay the exact same size no matter how much you zoom in. It's like a sticker on a window—the background gets bigger, but the sticker stays the same.

Sight Picture

The complete, clear view of the target and crosshairs when your eye is perfectly aligned behind the scope. It's the perfect camera framing right before you snap the photo.

Subsonic

A bullet traveling slower than the speed of sound, meaning it doesn't make a loud sonic crack. It's the stealth-mode ammunition for quiet shooting.

Supersonic

A bullet traveling faster than the speed of sound, creating a loud sonic boom in the air. It's a tiny fighter jet breaking the sound barrier.

Thread Pitch

The specific size and spacing of the screw threads on the end of the barrel. It's the exact nut-and-bolt measurement needed to attach a silencer or brake.

Twist Rate

How fast the spiral grooves inside the barrel spin the bullet to keep it stable in flight. 1:8 translates to; 8 inches = 1 full rotation.

V-Block Bedding

Also called: v block bedding, vblock betting

A precision V-shaped groove in MDT chassis that perfectly cradles the round rifle action without needing messy epoxy. It's a self-centering cradle that locks the engine into the frame perfectly every time.