It only takes a few minutes to produce a barrel in this way but the machinery is very expensive, which is why only larger manufacturers use this method. Button-rifled barrels are also made by drilling, grinding and polishing. The rifling pattern is then pressed into the barrel with a tool called a button. Afterwards the barrel is polished with a lead rod and grinding paste.
An antrum is a cavity or chamber, such as the antrum of the lower  part of the stomach. Erosion means that the lining is thinning,  resulting in inflammation and irritation.â¦ Erythema describes a  reddening of tissue due to irritation or injury. (MORE) 25 people found this useful.
A peptic ulcer (stomach or duodenal) is a break in the inner lining of the esophagus, stomach, or duodenum. A peptic ulcer of the stomach is called a gastric ulcer; of the duodenum, a duodenal ulcer; and of the esophagus, an esophageal ulcer. Peptic ulcers occur when the lining of these organs is corroded by the acidic digestive (peptic) juices which are secreted by the cells of the stomach.