Enfield pattern 1858/9. 
  
As a consequence of British fears, the native infantry's long arms were modified by reaming out the rifling of the Pattern 1853 as a smooth bore bullet does not require greasing. This greatly reduced the gun's effectiveness, as did replacing the variable distance rear sight to a fixed sight. This became the Pattern 1858. However, due to the new thinner walls, the barrel would bulge and bursting was not an unknown problem. Furthermore, with the bayonet fitted excessive flexing became an issue. To remedy this, new barrels were made with thicker walls. This became the