Challenger 1 Tank
The Challenger I tank first came into service with UK armed forces in March 1983. The Challenger 1 was fitted with a 120mm L11 rifled gun. Ammunition for the Challenger 1 included:
- L15 Armour Piercing Discarding Sabot (APDS) round with a tungsten penetrator (discontinued)
- L20 Discarding Sabot Training (DS/T) round
- L23 Armour Piercing Fin Stabilised Discarding Sabot (APFSDS) round with a tungsten penetrator
- L26 APFSDS round with a depleted uranium penetrator (also known as CHARM 1)
- L31 High Explosive Squash Head (HESH) round
- L32 Squash Head Practice (SH/Prac) round
- L34 White Phosphorus (WP) smoke round
UK tank ammunition is distinctive for two reasons - firstly it is fired from a rifled barrel, which is very unusual at the 120mm calibre. Secondly, the round is comprised of a separate projectile and charge. This design choice has limited the maximum penetrator length, and prevented armour piercing ammunition from being upgraded by simply changing the dimensions of the penetrator.
Development of the L26 round began before 1983, but the L26 was not brought into use until an upgrade made in 1991, prior to the Gulf War. The upgrade also included explosive resistant armour and a new projectile and charge system.
The name for the ammunition part of the programme was CHARM 1 (CHallenger ARmament), and it was originally intended to replace both the gun and the ammunition. In the event, a decision was taken to upgrade the projectile and charge only, and to bring forward a more fundamental upgrade of the tank. In time the name CHARM 1 became synonymous with the L26 APFSDS round, rather than the programme that produced it.
The fundamental upgrade of the Challenger 1 resulted in the Challenger 2 tank, and the UK's entire fleet was changed over to this later model by 2000. The UK's Challenger 1 fleet was transferred to Jordan. Jordan was never provided DU ammunition by the UK, and Jordanian Challenger tanks fire the L23 tungsten round.
In early 2011 it was reported that the UK was developing an improved L23 round for use in Jordanian Challenger 1 and Omani Challenger 2 tanks. An alternative penetrator material was being considered due to concerns about the standard tungsten alloy. This was to be designated the L23A2. ICBUW's report on this issue, and the outlook for UK DU ammunition is here.