This has bothered me for a long time: what kind of ammo Challenger 2 uses having a rifled cannon? HESH and HEAT with ball bearing were the only ones that I figured out.
To my knowledge (half remembered from things heard or read years ago), it's a APFSDS round, with the posibility of using depleted uranium rounds with less efectivity than smoothbore guns. Any british tanker can shed light on this?
From what I remember from 'Janes' and other sources, Challenger II does not use HE, HESH rounds fulfil this role against soft targets (along with co-ax mg of course). They definitely use DU APFSDS, at a guess I'd say the ball bearing idea was sound but I'm not sure if the sub-calibre has a counter spin or if spin is confined to the sabot. Hmm, anyone else know?
In Operations Desert Shield/Storm 176 Challenger 1s destroyed some 300 Iraqi tanks (no Challengers were destroyed). More than half of the engagements involved the use of HESH rounds.
Which proves that HESH is effective against 'standard' armour. However, most modern MBTs use layered armour, which HESH would be less effective against. Still, it is bloody good as knocking out bunkers/strongpoints (all this is simply my regurgitation of somebody else's knowledge in a different topic here! )
Some talking about rifled guns vs smoothbore, HESH vs HEAT etc from Tony Williams's forum: http://forums.delphiforums.com/n/mb/message.asp?webtag=autogun&msg=1685.1
Wheewwww, those guys lost me. I guess the gist is that the Brits likes the HESH rounds and it was believed to be more effective fired from a rifled cannon than a smoothbored, but this problem can be rectified by adding fins to the HESH rounds if fired from the latter?