#1 Kynoch Bren Cartridge has crimps on Mouth as if Bullet has been Pulled…Probably a Batch By Kynoch (originally Bulleted) for Bren Gun developments/Testing…who Pulled the Bullet?
#2 Kynoch .303: Ditto. This cartridge headstamp is a Kynoch “Commercial” type.
1 & 2 not necessarily " Grenade Launchers"…The Normal Card/Strawboard Wad of a Cordite Ball case was also varnished.
#3 Maxim 1895: Crimped Blank, made using “Maxim” marked Cases…Probably for in-house demonstration use, or sale with the their guns to both Gov’t and Private Buyers. Maxim-Nordenfeldt and Vickers-Maxim were not SA ammunition makers, but had their “Proprietrary” cartridges made by Kynoch or Eley.
#4 K1931 VII: Air Quality (Ball) Cartridge Case Loaded with Wooden Bullet for use in training on Aircraft Guns of the time (Lewis and Vickers Mod.K (GO)) Both of which required a full bullet profile Blank to feed correctly. May be for Export. The British Gov’t did not adopt a Wood Bullet Blank in .303 until late or after WW II (For Bren Guns, Cart. .303 Mark L10z).
#5 & 6 Kynoch SL “StreamLine” Bullet ( ie, Boat-tailed) used both for Military tests in 1930s, and also for Rifle Club Target Use ( ie, Bisley Matches).
Stain/Varnish marks indicate a variation in Bullet design/mass and also Cordite Charge, and also that these are “Special” Cartridges, not common Mark VII Ball.