Modern and vintage sporting guns and rifles can be worth tens of thousands of pounds and are much sought-after. Collectors tend to go for the earlier guns, but more recent, usable firearms are usually the most valuable and are popular with sports people.
Mr Gavin Gardiner, a specialist in sporting guns and other firearms at Sotheby's, says an advantage in pricing guns is that they almost all bear the maker's name. The big three names are James Purdey & Sons, Holland & Holland and Boss & Co. Any guns by these companies should fetch at least £500 or up to £40,000 at the top end of the market.
A rusty 12-bore hammer gun might normally be worth less than £50, but a similar gun in bad condition by J. Purdey & Sons should fetch about £500, he says.
Guns with a sidelock mechanism are technically superior and more valuable than boxlock guns. The sidelock gun looks more graceful and elegant when viewed from the side. A boxlock gun might be worth £1,000, while an otherwise identical sidelock gun should fetch between £3,000 and £5,000, says Mr Gardiner.
The bore of the gun can further enhance a gun's value. A lead ball weighing a twelfth of a pound will fit down the barrel of a 12-bore gun, the standard calibre. A 4bore gun is bigger it might be used for shooting geese while a 20-bore gun is smaller and lighter (the opposite to what you might expect).
Mr Gardiner says 20-bore guns have become very popular in the last 15 years. They used to be regarded as a woman's gun but this is no longer the case. They are quick to handle and give virtually the same performance as a 12bore gun and they don't "knock you around" as much.
An ejector, a development dating from about 1890, will also enhance a gun's value. That's the mechanism which automatically ejects the spent case after firing the gun and opening the barrel. (With a non-ejector gun, you have to pull out the empty case.) A boxlock gun with an ejector could be worth £800 to £1,000 compared to less than £200 for the non-ejector equivalent of the same gun.
Before 1860, guns were loaded from the muzzle, which took a lot of time, especially if the weather was wet. The correct amounts of loose-shot (the lead shot) and gunpowder had to be loaded, while reloading a double-barrelled gun was even more difficult.
Around 1860, the self-contained cartridge was introduced. Guns now opened from the breech the back end of the barrel and there was no longer a need to ram material in from the front. Shooting became a lot easier and took off as a sport.
Game shooting more or less began at this time and big organised shoots became possible. Before that, there was only "walkedup shooting" where a dog flushed out birds from bushes which had a slower pace.
The hammerless gun came in 1880. All of the mechanics of the gun were now self-contained. Before this, there was always an external part you had to pull back. But now there was a fully enclosed mechanism within the body of the gun, which re-cocked itself.
The term "vintage guns" generally describe those made between 1860 and 1880, even though Edward VII carried on shooting with them and George V, as late as 1931, had a pair of hammer guns built. Guns made after 1880 are considered "modern", says Mr Gardiner.
A hammer gun in good condition by Purdey & Sons made in 1890 might be worth about £1,500 today, while a hammerless gun by the same company would be worth about £5,000.
Mr Gavin Gardiner is happy to answer readers' queries about sporting guns and firearms. He can be contacted at Sotheby's, Summers Place, Billingshurst, West Sussex, RH14 9AD. Telephone: 0044 1403 833 500.
