text:  The decision to retain muzzle @-@ <unk> until the 1880s has been criticised by historians . However , at least until the late 1870s , the British muzzle @-@ <unk> had superior performance in terms of both range and rate of fire than the French and Prussian breech @-@ <unk> , which suffered from the same problems as had the first Armstrong guns . 
  