Evidently, the term "swamped" has been around for a really long time, in relation to guns. The first use I ever knew of was in regards to flintlock longrifle barrels. When draw filed to final shape they are/were tapered, octagonal, from the breech end towards the muzzle to a point roughly one foot back from the muzzle, at which point they gradually taper back larger toward the muzzle. It added elegance to barrel and more importantly lost some weight which made offhand shooting easier.

SRH

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