Glossary of Sniper Related Terms

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If there is a term you have heard that is not on this list, let us know and we’ll add it!

Minute of Angle (MOA) – This is a measure of angle that is 1/60th of one degree (As in 360 degrees in a circle). It is commonly used with shooting because it just so happens by pure coincidence that it is roughly 1″ at 100 yards. To be precise, it is 1.047″ at 100 yards. Since it is a measure of angle, it will grow as it gets further out. So 1 MOA is rought 1″ at 100 yards, 2″ at 200 yards, 3″ at 300 yards… 12″ at 1200 yards, until infinity. It is very handy for those that use the US system of measure to be able to easily make scope adjustments. I.e. if you are engaging a target 600 yards away and your first shot hit 12″ to the right, then the shooter would just need to dial in 2 MOA of left on the scope and then engage again. It is also commonly used to measure the accuracy of a rifle. If a group measures under .5″ at 100 yards, then it is said to be a “half MOA rifle.” Most people say “M” “O” “A” as three separate letters, though some call it moa, as if it were a word.. such as “mow-ah”. MOA is also used to easily dial in adjustments for different distances as well.

Sniper (Military)A soldier that is specially trained to seek out and deliver long range precision fire on key select targets and targets of opportunity. As a secondary role they additionally provide vital battlefield information to combat leaders. This information is gathered through expertise in trained reconnaissance skills. Traditionally a modern sniper team will operate in a two man team, but this can expand into larger teams as the mission dictates. <See a more detailed description here>

Sniper (Law Enforcement) – A specially trained law enforcement officer that specializes in delivering precision rifle fire that is intended to instantly incapacitate an individual, whom is threatening the lives of others, with a single precise shot. Typically snipers are assigned to, and train with, the SWAT or ERT team. <See a more detailed description here>

Sniper (common) – Anyone who takes a shot from a concealed position or at an unsuspecting person.

Designated Marksman (DM) – A specially trained soldier that specializes in long range precision rifle fire. They typically are assigned with traditional infantry squads to enhance that squad with the capability of extended range engagements and precision fire. They differ from a sniper primarily in their equipment and in that they are only trained in long range shooting skills and not in the fieldcraft and tactics that make up a sniper. <See a more detailed description here>

DMR (Designated Marksman Rifle) – A rifle that is specially designed for use by a DM (See above). Typically the rifle needs to be able to deliver not only precise long range rifle fire, but in a rapid manner. This usually means the rifles are semi-automatic, but that is not a strict requirement.

Sharpshooter – This is a term that often times refers to a sniper, but did originally describe anyone that is a crack shot, or a “sharpshooter”. Some consider it a more politically gentle term than sniper. Others will use the term to describe a Law Enforcement sniper, differentiating them from the military based term ‘sniper’.<See a more detailed description here>

Cartridge – The term cartridge refers to a specific piece of ammunition that includes a unique bullet and case. So the name 308 Winchester specifically refers to that brass and bullet with all of its official specifications. This is what many people incorrectly call the “caliber”.

Caliber – This refers to the diameter of anything circular, for shooters it is the diameter of the bullet. So when someone asks what “caliber” your rifle is, the correct answer would be something like .308 inches, or 7.62 millimeters. Many use this term when referring to the actual “Cartridge”.

Case – This typically is referring to the brass casing used for ammunition. Other terms are used in conjunction with the case, such as case head diameter, or case volume.

DBM (Detachable Box Magazine) – A DBM is a magazine that holds ammunition for the rifle to feed from and is also able to easily be removed, or detached, from the rifle.

Lugs – There are several different lugs on a rifle, most often the ones being referred to are the lugs on the bolt that mate to the lugs on the inside of the action. “Lapping the Lugs” refers to using a lapping process to smooth out and perfectly mate the bolt lugs to the actions lugs for improved accuracy.

Chamber – The portion of a rifle action where the complete cartridge is “chambered” or held when the rifle is loaded and fired.

Click/Klick – This has a couple of different meanings for snipers. A Klick in the military typically refers to 1 KM, or kilometer, or Klick for short. It can also mean 1 mile if using the English units. For snipers it also means one “click” on the scope adjustments. Such as, “Come up three clicks” would mean to dial in 3 clicks of up elevation on the scope. The size of the click depends on the scope being used, but the term “click” refers to the audible and tactical click that happens when adjusting the scope.

Milliradian (MIL, or MRad for short) – The term milli means 1/1000th, such as with the metric system. So a Milliradian is 1/1000 of a Radian, which is the measure of a central angle subtending an arc equal in length to the radius, which is equal to 57.2958 degrees. An easier way to describe how it is used for sniping, and specifically range finding, is that a Milliradian is 1 unit of measure at 1000 units of measure. By having this marked in a scope, or binos, or spotting scope, and knowing the size of the target, you can estimate the range to the target accurately by using the mil-relation formula. For reference, there are 3.437748 MOA in a Milliradian.

Hold off/Hold over – Refers to the method of aiming high, low, left, or right of the intended impact point of a shooter’s round in order to compensate for range, wind, moving targets, or any other variables that would cause the round to impact in a location other than where the shooter is aiming.

Trigger Creep – This term refers to any movement, or creep, of the trigger before it “breaks”, or “triggers” the sear to release the firing pin or hammer. A two-stage trigger will have a large amount of intended creep that constitutes the first stage.

Overtravel – Refers to any additional movement of the trigger to the rear after the trigger breaks and disengages the sear.

Extractor –The device, usually located on or near the bolt face, that “extracts” the case, or cartridge from the chamber of the rifle.

Tang – The top rear portion of a bolt action that extends toward the shooter and is where the bolt will slide into the action.

Ghillie Suit – A suit originally designed in the early 20th century by Scottish game wardens called “Ghillies”. A Ghillie Suit has burlap or jute strips and strings attached to the suit to create an extremely effective means of camouflage. The ghillie has become a normal part of the modern sniper’s kit and are typically built by hand.

Free Floating Barrel – This refers to nothing, specifically the stock, touching the barrel all the way back to the action or recoil lug, so it is “floating” free of any other objects. The theory is that if nothing is touching the barrel, it will allow the harmonics to be undisturbed and therefore help improve the accuracy of the rifle. Of course, there are those who believe that by having even pressure applied to the barrel at the front of the stock will actually reduce the barrel whip and will therefore improve the accuracy of the rifle. We have seen extremely accurate rifles done both ways, but we still prefer free floated barrels.

Crown/Recessed Crown – The crown refers to the muzzle end of the barrel where the bullet exits, specifically where the bore and rifling meet the abrupt end of the barrel. A good crown without nicks or blemish means the gases that are pushing the bullet down the barrel will exit uniformly all around the bullet and will not disrupts its path. A recessed crown means the crown is recessed back which will help prevent the crown from getting nicked from daily use. An 11 degree tapered crown refers to a recessed crown that has a tapered, non-stepped, crown cut at 11 degrees. This is thought to best improve the dissipation of the gases to again, help accuracy.

Rifling, Lands & Grooves – This refers to the actual spinning grooves that are cut into a barrel that grab the bullet and spin it for stability. The grooves are what is cut out of the barrel which leaves the “lands” sticking “up”.

Rate of Twist (ROT) – The rate of twist is the rate of which the rifling twists the bullet to provide its stabilizing spin. It references how much distance down the barrel it takes in order to make one full revolution. It is annotated as 1:10″. Meaning for every 1 rotation the rifling travels 10″ down the barrel. A smaller second number is regarded as a faster rate of twist. So a 1:10″ is considered a faster rate of twist than 1:12″. Typically, the longer the bullet (of the same caliber), the faster it will need to spin in order to stabilize it. So a 190gr 30 caliber bullet will need to spin faster than a 168gr 30 caliber bullet. This can be done by either speeding up the rate of twist, or speeding up the forward velocity of the bullet going down the barrel, which in turn will speed up the spin of the bullet.

Spin Drift – Because a bullet spins very very fast, it will exhibit a small amount of drifting in the direction of the rate of twist because of the spin as it pierces the air. This is kind of like a curve ball in baseball. So if a barrel has a right hand rate of twist, there will be a slight drifting to the right at long ranges. Many shooters do not compensate for the small amount of spin drift, though some competitive shooters do.

Coriolis Effect – This one is a bit tricky to describe. There is an amount of time that a bullet is in flight and while the bullet is in flight, the earth, and everything attached to it (like the target being shot at) continues to spin. So while the bullet is in flight, the target may actually move due to the spinning of the earth, even when the target is stationary. Of course, this only happens if the bullet flight is heading north or south, and the effect is smaller the closer to the north or south pole you are located. So if you are firing at a target directly north of you, the bullet impact will be slightly left, if you are shooting south, the impact will be slightly to the right. In reality, the effect is only noticeable at long ranges, and again, only if you are shooting north or south. If you are shooting at an angle, such as NorthWest, the effect is diminished.

Hollow Point Boat-Tail (HPBT) – This is a specific bullet design that is very common for match grade and long range bullets. The Hollow Point is a byproduct of manufacturing and is not designed to aid in the expansion of the bullet inside of tissue. The Boat-Tail refers to the design at the tail of the bullet and it tapers down, much like a boat hull does. This boat-tail design greatly enhances the aerodynamics of the bullet giving it greater long range capability. The HP manufacturing process has produced a very uniform bullet tip design which has also helped with accuracy, but some modern bullet makers have moved toward polymer tips to help with uniformity as well.

D.O.P.E (Data Of Previous Engagements) – This is a clever acronym for all of the data logged in a snipers log book. The dope can then be referenced for future engagements to determine what the correct adjustments should be for a given shooting scenario. Snipers typically log every shot they take in their DOPE books, and will often say things such as “What is the dope”, or “Give me the dope for this shot”. Or even “What dope do you have dialed in”.

If there is a term you have heard that is not on this list, let us know and we’ll add it!