Citation(s) from the GunPolicy.org literature library
Alpers, Philip. 2005 ‘Definitions: 'High-powered' Firearms.’ Gun-running in Papua New Guinea: From arrows to assault weapons in the Southern Highlands; Special Report No. 5, p. 22. Geneva: Small Arms Survey , the Graduate Institute of International and Development Studies. 1 July
The term 'high-powered firearm' is in common usage across Melanesia to describe a long gun or sub machine gun of the type normally issued to military and police. In Bougainville, peace monitors defined factory manufactured, military-style weapons (M16, AR15, SLR, FAMAS, SIG rifle, etc.) as 'highpowered'.
In the Solomon Islands, the International Peace Monitoring Team defined a military weapon as 'any high-powered centre-fire semi-automatic, automatic, bolt-action, magazine fed shotgun, riot gun, or signal pistol issued to members of the Solomon Islands police.' In common usage, Eastern bloc SKS rifles, AK-47 assault weapons, and their look-alikes, although never issued to state forces in the Melanesian region, are also referred to as 'high-powered firearms', as are semiautomatic, centrefire hunting rifles.
In short, this catch-all term is used to differentiate larger-calibre (centrefire), factory-made repeating long guns from single-shot shotguns, .22 calibre rimfire rifles, and home-made firearms.