W re x ham ▁Category : St ad iums ▁in ▁W re x ham <0x0A> </s> ▁The ▁ 5 0 ▁cal ib re ▁B L ▁ 6   inch ▁gun ▁Mark ▁XX III ▁was ▁the ▁main ▁battery ▁gun ▁used ▁on ▁the ▁Royal ▁Navy ▁and ▁British ▁Commonwealth ' s ▁conventional ▁( non - anti - air craft ) ▁light ▁cru is ers ▁built ▁from ▁ 1 9 3 0 ▁through ▁the ▁Second ▁World ▁War , ▁and ▁passed ▁into ▁service ▁with ▁several ▁other ▁nav ies ▁when ▁ships ▁were ▁dis posed ▁of ▁after ▁the ▁end ▁of ▁the ▁War . ▁ ▁Description ▁ ▁The ▁gun ▁replaced ▁the ▁B L ▁ 8 ▁in ch ▁M k ▁VIII ▁naval ▁gun ▁used ▁on ▁earlier ▁Washington ▁Naval ▁Tre aty ▁cru is ers . ▁ ▁These ▁built - up ▁guns ▁consisted ▁of ▁a ▁t ube ▁and ▁ 4 . 5 - met re ▁jack et ▁with ▁a ▁hand - oper ated ▁Wel in ▁b ree ch ▁block . ▁ ▁Cl oth ▁b ags ▁contained ▁ 1 4   kg ▁( 3 0 ▁p ound ) ▁charges ▁of ▁cord ite ▁or ▁flash less ▁( N Q FP ) ▁pow der ▁for ▁a ▁ 5 1   kg ▁( 1 1 2 - p ound ) ▁project ile . ▁ ▁Use ful ▁life ▁of ▁a ▁bar rel ▁was ▁ 1 1 0 0 ▁effective ▁full ▁charges ▁( E FC ) ▁with ▁standard ▁cord ite ▁and ▁ 2 2 0 0 ▁E FC ▁with ▁N Q FP . ▁The ▁typical ▁maximum ▁rate ▁of ▁fire ▁was