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33-402: The rifle is currently issued with match-grade M118LR 175- grain long range ammunition. The "basic" EMR (without telescopic sight , magazine , sling, basic issue items, cleaning gear, suppressor and bipod ) weighs 13 pounds (5.9 kg) or less. In November 1992, Marine Corps Systems Command drafted a mission needs statement for an enhanced sniper support team weapon (SSTW). It called for

66-572: A definition of the meter in terms of the yard, and the kilogram in terms of the pound. In 1893, the Mendenhall Order changed the fundamental standards of length and mass of the United States from the customary standards based on those of England to metric standards. There were two factors that influenced the order: for one, the imperial standard yard of 1855 had been found to be unstable and shortening by measurable amounts. Secondly,

99-449: A new formal definition of the yard. Two copies of the ruler were subsequently presented to the United States, which in turn adopted the measure for the United States national standard yard. In 1866, the U.S. Congress passed a law that allowed, but did not require, the use of the metric system in trade and commerce. Included in the law was a table of conversion factors between the customary (i.e. English-derived) and metric units, among them

132-691: A program unto themselves and culminated as the M39 Enhanced Marksman Rifle. There are several differences between the DMR and EMR. The EMR is primarily used by a designated marksman , to provide precision fire for units that do not rate a scout sniper . As a replacement for the DMR, the EMR fills the need for a lightweight, accurate weapon system utilizing a cartridge more powerful than the M16A4's standard 5.56×45mm NATO—the 7.62×51mm NATO. The EMR

165-420: A recommendation that the meter be defined in atomic terms (specifically in terms of the orange line of krypton-86 ). To secure identical values for the yard and pound in precise measurements, representatives of six English-speaking nations—Australia, Canada, New Zealand, South Africa, United States and United Kingdom—agreed to adopt a common 'international yard and international pound'. According to that agreement,

198-559: A weapon to support the M40A1 sniper rifle in a Scout Sniper team for close-range engagements and to lay down rapid semiautomatic suppressive fire. At the time, the role was filled by the M16A2 , which could not mount optics or night vision sights and used M855 5.56×45mm NATO ammunition, which was too inaccurate for the role. A previous designated marksman weapon effort attempted to use the M14 for

231-552: Is a unit of measurement of mass , and in the troy weight , avoirdupois , and apothecaries' systems , equal to exactly 64.798 91  milligrams . It is nominally based upon the mass of a single ideal seed of a cereal . From the Bronze Age into the Renaissance, the average masses of wheat and barley grains were part of the legal definitions of units of mass. Expressions such as "thirty-two grains of wheat, taken from

264-900: Is also used by Marine scout snipers when the mission requires rapid accurate fire and by Marine Corps explosive ordnance disposal teams. In early 2012, the Marine Corps began replacing the M39 with the M110 Semi-Automatic Sniper System , originally developed for the U.S. Army , on a one-for-one basis, with the designation of Mk 11 Mod 2. The M110 better fills the requirements of the SSTW, being able to mount suppressors and night vision systems while maintaining zero, and having M16 training and supply commonality. [REDACTED] Media related to M39 Enhanced Marksman Rifle at Wikimedia Commons Grain (measure) A grain

297-425: Is measured in the dimensionless unit of parts per million ( ppm ), numerically equivalent to concentration measured in milligrams per litre. One grain per U.S. gallon is approximately 17.1 ppm . Soft water contains 1–4 gpg of calcium carbonate equivalents, while hard water contains 11–2 gpg . Though no longer recommended, in the U.S., grains are still used occasionally in medicine as part of

330-417: Is mg/ m . One grain per cubic foot is approximately 2288 mg/m . At least since antiquity , grains of wheat or barley were used by Mediterranean traders to define units of mass; along with other seeds, especially those of the carob tree. According to a longstanding tradition, one carat (the mass of a carob seed) was equivalent to the weight of four wheat grains or three barleycorns. Since

363-497: Is obsolete in the United Kingdom and, like most other non-SI units, it has no basis in law and cannot be used in commerce. Grains are commonly used to measure the mass of bullets and propellants . In archery, the grain is the standard unit used to weigh arrows. In North America, the hardness of water is often measured in grains per U.S. gallon ( gpg ) of calcium carbonate equivalents. Otherwise, water hardness

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396-547: Is thus approximately equivalent to 15.432 36  grains . The unit formerly used by jewellers to measure pearls, diamonds, and other precious stones, called the jeweller's grain or pearl grain , is equal to 1 ⁄ 4 carat (50 mg; 0.77 gr). The grain was also the name of a traditional French unit equal to 53.115 mg . In both British Imperial units and United States customary units , there are precisely 7,000 grains per avoirdupois pound , and 5,760 grains per troy pound or apothecaries' pound. It

429-484: The Houses of Parliament . The standard was an avoirdupois pound, the grain being defined as ⁠ 1 / 7000 ⁠ of it. The division of the carat into four grains survives in both senses well into the early twentieth century. For pearls and diamonds, weight is quoted in carats, divided into four grains. The carat was eventually set to 205 milligrams (1877), and later 200 milligrams. For touch or fineness of gold,

462-565: The International Bureau of Weights and Measures provisionally adopted the 1908 light-wave definition of the meter as a supplemental standard. In 1930, the British Standards Institution adopted an inch of exactly 25.4  millimetres (mm), based on the 1927 light-wave definition of the meter. The American Standards Association followed suit in 1933. By 1935, industry in 16 countries had adopted

495-458: The apothecaries' system , especially in prescriptions for older medicines such as aspirin or phenobarbital . For example, the dosage of a standard 325 mg tablet of aspirin is sometimes given as 5 grains . In that example the grain is approximated to 65 mg , though the grain can also be approximated to 60 mg , depending on the medication and manufacturer. The apothecaries' system has its own system of notation, in which

528-495: The yard as exactly 0.9144  meters and the avoirdupois pound as exactly 0.453 592 37   kilograms . In October 1834, the British Houses of Parliament were destroyed in a fire . Among the items lost were the objects that defined the imperial standards of length and mass. New prototypes were subsequently created to replace the items lost in the fire, among them a new "yardstick" ruler in 1855, and with it

561-788: The "industrial inch" as it came to be known. In 1946, the British Commonwealth Scientific Conference recommended that members of the British Commonwealth adopt the inch as exactly 25.4 mm, and the 36-inch yard as exactly 0.9144 meters. The British Commonwealth Scientific Conference's recommendations were accepted by the Canadian Standards Association in 1951. In October 1958, the International Committee on Weights and Measures made

594-507: The British definitions were reversed, resulting in a de facto definition of the imperial yard as 36/39.370113 meter. In the 1890s, Albert Michelson began conducting experiments in interferometry that led in 1903 to demonstrating the feasibility of using light waves as units of linear measurement. In 1908, two teams of researchers, one led by Michelson, defined the length of the international prototype meter in terms of light waves. In 1927,

627-612: The United States was a co-signee of the Treaty of the Metre of 1875 and had received two meter prototypes on which to base a new fundamental standard. In the United Kingdom, a similar situation developed with the Weights and Measures Act 1897 legalizing the metric system, and Order in Council 411 (1898) defining the meter and kilogram in terms of the yard and pound. As a practical matter

660-547: The fraction of gold was given as a weight, the total being a solidus of 24 carats or 96 grains. International yard and pound The international yard and pound are two units of measurement that were the subject of an agreement among representatives of six nations signed on 1 July 1959: Australia , Canada , New Zealand , South Africa , the United Kingdom and the United States . The agreement defined

693-547: The international yard equals 0.9144 meters and the international pound equals 0.45359237 kilograms. The international yard was about two millionths of a meter longer than the imperial yard, while the international pound was about six ten-millionths of a kilogram lighter than the imperial pound. The metric-based international yard and international pound were adopted by the United States National Bureau of Standards effective 1 July 1959. In Australia,

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726-526: The lesser but quicker balances: the bismar or auncel, the Roman balance, and the steelyard . The original mercantile pound of 25 shillings or 15 (Tower) ounces was displaced by, variously, the pound of the Hanseatic League (16 tower ounces) and by the pound of the then-important wool trade (16 ounces of 437 grains). A new pound of 7,680 grains was inadvertently created as 16 troy ounces, referring to

759-451: The metric system, and the use of the grain in prescriptions is now rare. In the U.S., particulate emission levels, used to monitor and regulate pollution, are sometimes measured in grains per cubic foot instead of the more usual ppm by volume. This is the same unit commonly used to measure the amount of moisture in the air, also known as the absolute humidity . The SI unit used to measure particulate emissions and absolute humidity

792-602: The middle of the ear" appear to have been ritualistic formulas. Another source states that it was defined such that 252.458 units would balance 1 cubic inch (16 cm ) of distilled water at an ambient air-water pressure and temperature of 30 inches of mercury (100 kPa) and 62 °F (17 °C) respectively. Another book states that Captain Henry Kater , of the British Standards Commission, arrived at this value experimentally. The grain

825-479: The new troy rather than the old troy. Eventually, the wool pound won out. The avoirdupois pound was defined in prototype, rated as 6,992 to 7,004 grains. In the Imperial Weights and Measures Act 1824 ( 5 Geo. 4 . c. 74), the avoirdupois pound was defined as 7,000 grains exactly. The Weights and Measures Act 1855 authorised Miller's new standards to replace those lost in the fire that destroyed

858-444: The original sterling pennies was 22½ troy grains, or 32 "Tower grains". Physical grain weights were made and sold commercially at least as late as the early 1900s, and took various forms, from squares of sheet metal to manufactured wire shapes and coin-like weights. The troy pound was only "the pound of Pence, Spices, Confections, as of Electuaries", as such goods might be measured by a troi or small balance. The old troy standard

891-584: The role, but it was not as accurate as bolt-action rifles and could not fit into the Fleet Marine Forces logistics system. The enhanced SSTW had to engage targets out to 600 meters, use ammunition interchangeable with the M40A1, be able to mount a sound suppressor and optics, and be supportable. Even though the M14 was not initially suitable, rifle equipment builders continued to refine it and produced versions as "interim measures". They eventually became

924-555: The units symbol or abbreviation is followed by the quantity in lower case Roman numerals . For amounts less than one, the quantity is written as a fraction, or for one half, ss (or variations such as ss., ṡṡ, or s̅s̅). Therefore, a prescription for tablets containing 325 mg of aspirin and 30 mg of codeine can be written "ASA gr. v c̄ cod. gr. ss tablets" (using the medical abbreviations ASA for acetylsalicylic acid [aspirin], c̄ for "with", and cod. for codeine). The apothecaries' system has gradually been replaced by

957-432: The weights of these seeds are highly variable, especially that of the cereals as a function of moisture, this is a convention more than an absolute law. The history of the modern British grain can be traced back to a royal decree in thirteenth century England, re-iterating decrees that go back as far as King Offa (eighth century). The Tower pound was one of many monetary pounds of 240 silver pennies . By consent of

990-645: The whole Realm the King's Measure was made, so that an English Penny , which is called the Sterling, round without clipping, shall weigh Thirty-two Grains of Wheat dry in the midst of the Ear; Twenty pennies make an Ounce; and Twelve Ounces make a Pound. The pound in question is the Tower pound . The Tower pound, abolished in 1527, consisted of 12 ounces like the troy pound, but was 1 ⁄ 16 (≈6%) lighter. The weight of

1023-502: Was based on the wheat grain. The tower "wheat" grain was defined as exactly + 45 ⁄ 64 (≈ + 3 ⁄ 4 ) of the troy "barley" grain. Since the implementation of the international yard and pound agreement of 1 July 1959, the grain or troy grain (symbol: gr ) measure has been defined in terms of units of mass in the International System of Units as precisely 64.798 91   milligrams . One gram

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1056-451: Was set by King Offa's currency reform , and was in full use in 1284 (Assize of Weights and Measures, King Edward I), but was restricted to currency (the pound of pennies) until it was abolished in 1527. This pound was progressively replaced by a new pound, based on the weight of 120 silver dirhems of 48 grains. The new pound used a barley-corn grain, rather than a wheat grain. Avoirdupois (goods of weight) refers to those things measured by

1089-406: Was the legal foundation of traditional English weight systems , and is the only unit that is equal throughout the troy, avoirdupois, and apothecaries' systems of mass. The unit was based on the weight of a single grain of barley which was equal to about + 4 ⁄ 3 the weight of a single grain of wheat. The fundamental unit of the pre-1527 English weight system, known as Tower weights ,

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