Every serious sportsman knows that by late August, the Scottish Highlands offer an array of riches. Grouse season is a couple weeks under way. Deer stalking is at its peak, and the fly-fishing doesn’t get any better.

Sotheby’s annual sale of antique sporting guns at the Gleneagles Hotel in Scotland is popular this time of year because winning bidders can walk out the door and take to the field with their elegantly engraved rifles and shotguns. City bankers and sundry members of the English upper class have always favored the Highlands in August (and the golf is phenomenal, too).

But at Sotheby’s 35th annual Gleneagles auction on Monday, it’s visitors from North America — particularly financiers from Wall Street’s most storied shops — who are expected to keep the market for antique British guns smoking hot. “Thank goodness for the Americans,” Sotheby’s specialist for vintage and modern sporting guns, Gavin Gardiner, said. “The wealthy gun connoisseurs there have really created a significant demand in the high end of the market.”

The top British manufacturers — including venerable firms such as Holland & Holland, Boss & Co., and James Purdey & Sons — are well represented at next week’s sale. Indeed, evidence of Britain’s sporting gun renaissance of the past quarter-century is on display at auctions such as the one at Gleneagles.

Collectors of antique guns generally agree that the period between the late 19th century and the outbreak of World War II was the high point of the country’s gun making. After the war, Britain experienced an enormous amalgamation of firearms companies; the recession of the 1980s virtually wiped out the middle-market manufacturers, leaving only the extremely high-end creators. What’s left today is the crème de la crème of British sporting guns.

One of the best aspects of the Gleneagles event is that modern and antique pieces from these firms will be sold side by side. So much so that the finest lot of the Sotheby’s sale cannot be called an antique: It’s a Holland & Holland .470 nitro express sidelock ejector rifle completed in 1995, estimated at between $100,000 and $140,000. The gun has 24-inch chopper-lump barrels with engraved breaches. The bolstered frame, locks, and top lever are all elaborately engraved as well with scenes of African game such as zebras, elands, and a lion. “This is a fantastic example of a fairly modern big-game rifle,” Mr. Gardiner said. “It’s ideal for taking down an elephant or a rhino, but it might actually be a bit too big for a lion.”

Although it’s not the oldest item in the sale, ordering a brand new elephant gun of this quality from Holland & Holland would most likely take three years and cost upwards of $200,000, according to Mr. Gardiner.

A vintage Holland & Holland pigeon gun from 1961 was originally the property of the famous American sportsman Russell B. Aitken. The competitive marksman and hunter used this 12-bore, single-trigger, self-opening sidelock ejector pigeon gun for shoots in Barcelona, Spain — one of the last places where outdoorsmen can still shoot live pigeons. The gun retains nearly all its original hardening color.

The shotgun, which is estimated to sell for between $40,000 and $60,000, originally had double triggers. But Mr. Aitken had the side-by-side model refitted with one trigger, which allowed him more quickly and effectively to hit the pigeons. (In competitive pigeon shooting, the bird must die within the marked boundaries of the field for the shooter to score.)

Aficionados of over-under models will appreciate the Boss & Co. 12-bore, single-trigger sidelock ejector gun, estimated to sell for between $80,000 and $100,000. “The design dates back to 1909 and fewer than 400 guns have been made by the company in those nearly 100 years. Not only is it scarce; nobody’s built a better model in this category since 1909,” Mr. Gardiner said.

The Boss sports 28-inch barrels with 2 3/4-inch chambers. The frame, locks, and top lever boast fine scroll and bouquet engraving. Like the Holland & Holland that once belonged to Mr. Aitken, this Boss retains much of its original hardening color.

At every antiques sale, certain models that hit the block are too elaborately engraved for frequent use in the field. At Gleneagles next week, a pair of Keith Thomas-engraved presentation guns will be granted that distinction. It is estimated at between $130,000 and $150,000.

The master engraver Mr. Thomas created game scenes against the backdrop of the royal palaces of England and a cross of St. George on the first gun; the royal castles of Scotland and a cross of St. Andrew are on the second model. Both are side-by-side, 28-bore self-opening sidelock ejector guns manufactured by Watson Bros. of London. “This pair might be used by the new owner, but certainly not every day,” Mr. Gardiner said.

jakasie@nysun.com