It's 175 years since the first Colt - and it still blows away the competition

On this day in 1836, American inventor Samuel Colt was granted a patent for his famous revolver - and firearms would never be the same again.  The iconic design revolutionised the production of guns, allowing handguns to be fired repeatedly without reloading after every shot.

Colt revolvers were used in the Mexican-American War, the American Civil War, the Crimean War, and at the Battle of Little Bighorn between the US army and the Sioux Indians.  Colts have also been used widely in movies - for example, Clint Eastwood famously brandished a .44 Magnum in 'Dirty Harry'.

The innovative design of the weapon was based on a revolving cylinder, usually with six chambers.  As the hammer of the gun was cocked, the cylinder revolves to align the next round with the hammer and barrel, allowing several rounds to be fired in quick succession.

Colt's contributions to the gun industry are almost unmatched; he pioneered the use of interchangeable parts in guns and pushed for the introduction of assembly line production of the weapons.  His contributions have been described as "events which shaped the destiny of American Firearms".

'Golden opportunity' - a fine Colt Bisley revolver, worth just under $5,000

The Colt has also had a significant impact on the militaria market as well.  In 2008, James D Julia Auctions auctioned a rare Colt Walker - made for US Marshals in the Mexican-American war.  It broke all previous records for the sale of a single firearm, selling for $920,000.

In the same auction, a fluted Colt model from 1860, with its stock included, realised $454,000.  A year later, the auction house sold an engraved and gold inlaid Single Action Colt for $747,500.  Recently, Don Presley auctions offered a .44 calibre A2-1 1882 Colt - only one of 20 in existence - for $75,000, but it failed to sell.

At the lower end of the scale, a beautifully engraved and gold-plated 1898 Colt Bisley revolver with ivory grips - complete with mahogany case - sold for $4,818.  Next week, Affiliated Auctions of Florida will be offering a 1907 Colt revolver for sale, formerly owned by well-known cowboy actor and Wyatt Earp associate, William Hart.  It has an estimate of $7,000-10,000.

The Colt really is a unique and historic gun, and a good militaria investment.  While some collectors will be interested in their practical and mechanical features, others will be attracted to the simply stunning designs of others - for example, the Colt Bisley pictured above.  Either way, the Colt remains an influential and coveted item nearly two centuries after its invention.