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.
Gastric Antrum. Gastric Antrum: Gastric Antral Vascular Ectasia or GAVE is a rare origin of gastrointestinal bleeding that is chronic as well as anemia from the loss of blood. This condition is associated with small blood vessels dilating in the gastric antrum. The dilated vessels cause intestinal bleeding.