In guns firearms, caliber is the specified nominal internal diameter of the gun barrel bore regardless of how or where the bore is measured and whether or not the finished bore matches that specification. It is measured in inches in millimeters. For example, a ".45 caliber" firearm has a barrel diameter of 0.45 inches. Barrel diameters can be expressed using metric dimensions. For example, a "9 mm pistol" has a barrel diameter of about 9 millimeters. Due to the inaccuracy and imprecision of imperial dimensions "converted" to metric units, metric designations are far out of specifications published in decimal inches. True "caliber" specifications require imperial measure, when cartridge designations only specify caliber to tenths or hundredths of an inch, actual barrel/chamber/projectile dimensions are published to at least thousandths of an inch and tolerances extend into ten-thousandths of an inch. In a rifled barrel, the distance is measured between opposing grooves. Measurements "across the grooves" are used for maximum precision because rifling and the specific caliber so-measured is the result of final machining process which cuts grooves into the rough bore leaving the "lands" behind.

Good performance requires a concentric, straight bore that centers the projectile within, in preference to a "tight" fit which can be achieved with off-center, crooked bores that cause excessive friction, fouling and an out-of-balance, wobbling projectile in flight. While modern firearms are referred to by the name of the cartridge the gun is chambered for, they are still categorized together based on bore diameter. For example, a firearm might be described as a "30 caliber rifle", which could be any of a wide range of cartridges using a 0.30 inches projectile. However, there can be significant differences in nominal bullet and bore dimensions and all cartridges so "categorized" are not automatically identical in actual caliber. For example.303 British firearms and projectiles are "categorized" as ".30-caliber" alongside several dozen U. S. ".30-caliber" cartridges despite using bullets.310-.312" diameter while all U. S".30-caliber" centerfire rifle cartridges use a standard.308" bullet outside diameter.

Using bullets larger than design specifications causes excessive pressures while undersize bullets cause low pressures,insufficient muzzle velocities and fouling that will lead to excessive pressures. Regardless of common practice among "shooters", caliber refers to specific and crucial bore/bullet dimensions and generic categorizations involving "caliber" are of little benefit to the shooting and arms industries. Calibers fall into four general categories by size. Small-bore refers to calibers with a diameter of smaller; the medium-bore refers to calibers with a diameter between.33 inches up to.39 inches and large-bore refers to calibers with a diameter of.40 inches or larger. Miniature bore referred to calibers under.22. There is much variance in the use of the term small-bore which over the years has changed with anything under.577 caliber considered small-bore prior to the mid-19th century. Makers of early cartridge arms had to invent methods of naming cartridges since no established convention existed then.

One of the early established cartridge arms was the Spencer repeating rifle, which Union forces used in the American Civil War. It was named based on the chamber dimensions, rather than the bore diameter, with the earliest cartridge called the "No. 56 cartridge", indicating a chamber diameter of.56 in. Various derivatives were created using the same basic cartridge, but with smaller-diameter bullets; the original No. 56 became the.56-56, the smaller versions.56-52.56-50, and.56-46. The.56-52, the most common of the new calibers, used a 50-cal bullet. Other black powder-era cartridges used naming schemes that appeared similar, but measured different characteristics. Optionally, the bullet weight in grains was designated, e.g..45-70-405. This scheme was far more popular and was carried over after the advent of early smokeless powder cartridges such as the.30-30 Winchester and.22 Long. Developments used terms to indicate relative power, such as.44 Special and.44 Magnum. Variations on these methods persist today, with new cartridges such as the.204 Ruger and.17 HMR.

Metric diameters for small arms refer to cartridge dimensions and are expressed with an "×" between the bore diameter and the length of the cartridge case. The means of measuring a rifled bore varies, may refer to the diameter of the lands or the grooves of the rifling. For example, the.257 Roberts and.250 Savage both use a.250 inch projectile. The.308 Winchester uses a.308-in diameter bullet.

Mariano Martinez (entrepreneur)

Mariano Martinez is a Mexican American inventor, entrepreneur and creative artist. In Dallas, Texas, in 1971, he adapted a soft serve ice cream machine to making margaritas and dubbed it "The World’s First Frozen Margarita Machine"; that machine is now in the collection of the National Museum of American History, part of the Smithsonian Institution. Martinez was born in Texas, in the Little Mexico neighborhood. Spanish was his first language, but when he was five years old, his family was the first Mexican-American family to move into Lakewood, where he learned to speak English so he could attend school. At the age of nine, he began working in his father's Mexican restaurant as a busboy, he dropped out of high school to work. He played electric bass guitar for a Dallas rock band, but found that he had only average talent as a musician, so decided to go back to school, he obtained his GED at the age of 21 and an associate degree in business from El Centro College. In 1973, Mariano married Wanda Wade.

In 1971, Martinez opened his first restaurant, Mariano's Mexican Cuisine, in Dallas by selling everything he owned to obtain a S. B. A. Loan. Mariano owns and operates six Mexican restaurants in North Texas that employ more than 600 people and serve 1.3 million guests per year. Martinez used his father's margarita recipe in his new restaurant. Mariano used his show business contacts to generate word-of-mouth about the new Mexican restaurant, Mariano's Mexican Cuisine, which resulted in large crowds. Demand for his blended margarita was high, but the bar staff could not keep up with orders, as over 200 per night were produced from just one blender. Customers complained that the drinks tasted different each time, Martinez realized that his bartenders did not take the time to measure out the drink's ingredients, his head bartender threatened to quit. Faced with both unhappy bartenders and dissatisfied customers, Martinez resolved to find a better way. At a local 7-Eleven, he noticed the Slurpee machine, he realized he could premix the margarita and the bartenders would pull the lever to dispense it.

He tried to buy a frozen drink machine but was told no, as they were leery of his intention and said his idea would not work because alcohol does not freeze. Martinez bought a used ice cream machine on May 11, 1971 and modified the machine and his recipe to make frozen margaritas, it was a "simple spigot with a lever, a steel cup holder in which to place a glass, some buttons and vents". The machine was moved to Mariano's bar where it was placed front and center, soon customers began to ask for the frozen margarita by name. At this time, Texas prohibited selling liquor by the glass in the dining rooms of restaurants, so Mariano's Mexican Cuisine was operated as a private club, but in 1971, the law was changed to allow restaurants in wet counties to sell cocktails by the glass. Sales of the popular frozen margarita soared as a result, Mariano's became the destination for cocktails in Dallas; as popularity of the drink increased and word of mouth traveled, other versions of The World's First Frozen Margarita Machine hit the market and became standard bar equipment.

This was due in part to Mariano's lack of a patent on the machine. Mariano never sought to be an inventor, he wanted to keep his doors open, protect his reputation and live the American Dream of owning his own business. In the process of doing so, he impacted several industries; the frozen margarita machine streamlined the process of making frozen margaritas, increasing U. S. demand for the unknown Mexican spirit tequila, contributed to the popularity of the Tex-Mex cuisine with which it was paired. In 2005, after 34 years at the original location of Mariano's Mexican Cuisine, Mariano retired the original frozen margarita machine and donated it to the Smithsonian's National Museum of American History. In September 2010, in celebration of National Inventors Month,'s "Around the Mall" blog announced the "Top Ten Inventions from the National Museum of American History’s Collection", with Martinez's frozen margarita machine as number ten. On November 20, 2012, an exhibition at the Smithsonian’s National Museum of American History, FOOD: Transforming the American Table, 1950-2000 included Martinez's invention.

On October 14, 2019, Jimmy Kimmels own Guillermo came by Mariano's Hacienda with Dallas Cowboys quarterback Tony Romo to enjoy margarita with Mariano and friends. Guillermo's Road Trip to Brooklyn: Stop #1 – Dallas with Tony Romo On July 20, 2011, ABC’s Nightline interviewed Mariano and told his life story. ABC Nightline Mariano Martinez received Special Recognition by The City of Dallas Dallas City Council Proclamation Mariano Martinez received Honor as the Inventor of the Margarita Machine by State of Texas Proclamation State of Texas Proclamation - Mariano Martinez Inventor of Margarita Machine Rachael Ray's Tasty Travels filmed at Mariano’s. On May 11, 2001, the City of Dallas named Mariano’s frozen margarita as the "Official Drink of Dallas", noting it as a national drink sensation, alongside New York's Manhattan cocktail and New Orleans’ Hurricane. In 1978, Mariano's accomplishments were recognized in a four-page chronicle of his life, read into the Congressional Record in Washington, D.

C. The United States Small Business Administration presented Martinez with the Minority Business Enterprise of the year Award in May 1984. Martinez received special recognition from the Dallas City Council on February 16, 2006 for "building a Dallas business that helped transform Tex-Mex cuisine into an American favorite". Martinez was congratulated by the White House on his induction into the Smithsonian Institution in Washington D. C

Golden Fleece Company

Golden Fleece was an Australian brand of petroleum products and service stations operated by H. C. Sleigh and Company. A partnership was founded in Melbourne, Australia in 1893 by shipowner and merchant Harold Crofton Sleigh and manufacturer and shipowner John McIlwraith. In 1913 the company took delivery of its first consignment of motor spirit from the United States and marketed it in Australia as "Golden Fleece". Motor spirit was sold in drums only—the first Golden Fleece pump being installed in 1920. Golden Fleece was a pioneer of single-branded service stations, its distinctive "golden merino" trademark was soon a common sight for Australian motorists; the post-war era saw a massive expansion of Australia's motor car ownership soared. The company was made public in 1947; these were boom times for Golden Fleece and expansion and acquisitions were the trend throughout the 1950s and 1960s. H. C. Sleigh Limited acquired the fledgling "Kangaroo" and "Phillips 66" brands in 1962 and 1967 respectively.

During these years, many Golden Fleece service stations became roadhouse-style outlets with restaurants and bold signage. Some time during the 1960s or 1970s Golden Fleece gained a major contract by the small, major trucking company Linfox, still held by Caltex Australia today, due to a friendship between Regional Manager for Victoria Max Collins and Lindsay Fox; the company never had its own oil refinery and depended on Caltex to facilitate the importation and refining of crude oils at Kurnell Refinery in Sydney on its behalf. In the late 1970s the industry started to mature and rationalise due to soaring crude oil prices, Federal Government oversight of petrol and diesel prices, a subtle form of price control. Golden Fleece was itself acquired by Caltex in 1981 and no longer trades under that name, though its unique livery can still be seen on some older roadhouses in rural Australia. A particular treasure for collectors are the globes that sat atop the company's pumps until the 1970s, when the pumps were standardised.

Purr Pull was a brand marketed by Independent Oil Industries of Sydney. They sold Purr Star and Resis Oil; the company was bought out by Smith Wylie Pty Ltd in Queensland who ran the company as Purr Pull Industries and in June 1954, H. C. Sleigh merged with Purr Pull Industries, with the Purr Pull and Star brands dropped and all operations rebranded as Golden Fleece. Harold Crofton Sleigh, co-founder and Chairman John McIlwraith 1893–1902, co-founder Hamilton Moreton Sleigh Chairman and CEO 1933–1975 Peter Sleigh 1975–1981 Chairman and CEO