The Belgian name "Mitrailleuse d'Appui General", or general-purpose machine gun (GPMG), became popular for describing medium machine guns used in multiple roles. The mediums fired full-power rifle-caliber ammunition, but had some concessions for more extended firing and more general usage. This generally included both bipod and tripod/pintle mounting options and quick-change barrels. Water-cooled machine guns of the same caliber as the existing mediums were no longer useful, as the situation in which they excelled (non-stop firing) was regarded as no longer being needed in modern warfare. This is because mass charges by infantry are rarely done, replaced by ARV-based thrusts, and that a static MG position is a high-priority target for infantry rocket launchers. Modern medium machine guns do not match the sustained firing ability of many older mediums; there is no longer a need for it. Most medium machine guns that use barrel replacement overheat after about 200 rounds, and then a quick barrel replacement is needed (such as was done on the Bren). They can only keep firing if they have spare barrels. However, barrels are expensive and heavy, so only a limited amount are kept. As a result, even if two or three barrels were carried and rotated in and out, it would not allow non-stop fire; the removed barrel does not cool down before the next must be replaced. This has become a moot point, since situations where non-stop fire is needed is rare, and other tactics and weapons can deal with an emergency.