Barrels can be manufactured at shorter lengths as an alternative to traditional, longer barrels. Oil and gasoline are traded in units of 1,000 barrels (42,000 US gallons). It also does very well in rifles with less than barrels. They had to sight their guns by looking under the barrels. It also ranks fourth in oil reserves with an estimated 153,600,000,000 barrels. The maps contain caves, bridges, poison gas, explosive barrels, and more. Most wines aged in charred oak barrels possess tannins absorbed from the wood. Modern slugs are moderately accurate, especially when fired from special rifled slug barrels. Venezuela estimates its recoverable oil at 267 billion barrels (42 billion m). It held 15,000 barrels () of bourbon. The beer barrels at the tavern were emptied. SIGP556 pistol variants with 10 in barrels are also available. Special revolvers with four-inch barrels. The reserves amount to 1.3 bn barrels. These were covered with salt and shipped in wooden barrels.