Complex sentence: The No.36M remained the standard grenade of the British Armed Forces until the introduction of the L2 series in the 1970s although it still remains in service in some parts of the world though, such as India and Pakistan.
Split into simpler sentences: The No.36M remained the standard grenade of the British Armed Forces until the introduction of the L2 series in the 1970s. The 36M still remains in service in some parts of the world, such as India and Pakistan.