A device for the dispensing of powderis of the type in which a generated gas flow entrains the powder to be dispensed and carries the powder from the device via barrel (29). The barrel has a bore including a main portion (294) with a continuous internal surface, and is characterised in that (a) the length of the main portion is at least fifteen times its maximum internal diameter and/or (b) the internal bore of the main portion is tapered and/or (c) the barrel has an outwardly flared outlet portion (292).