Ah!
It is the one where there is a sleeve to take it down from 5.56 to .22?
/weird cross measurement conversion blog
(
LordManley twitter.com/LordManley,
Sun 14 Jan 2007, 19:05,
archived)
sorry
beyond my knowledge now! All I did was point them at pictures of helicopters for 6 months until I realised that military activities weren't my thing.
(
naeonlite,
Sun 14 Jan 2007, 19:08,
archived)