30mm Cannons Destroy Russian Armored Vehicles in Ukraine

By Julian Nettlefold,

Reports emanating from Ukraine demonstrate the effectiveness of current 30mm canon systems against Russian APCs and the BMP-4 in particular. This puts a big question mark over the threat analysis conducted in the 1990s which saw a need for 40mm and the CT-40 canon in particular, to defeat the BMP-4. Has the decision by the US to go for 50mm in 2020 also been found wanting? 

The Argument for 40mm 

So how does CTA technology allow the CT40 cannon to perform above its competition? Due to the nature of telescoped ammunition, CTA ammunition has 30 percent more performance for the same volume of ammunition. This can be seen in a comparison of the size of the rounds: forty-millimeter CT ammunition is only the size of conventional thirty millimeter ammunition while delivering performance on par with conventional forty-millimeter rounds. 

Talking in numbers, the forty-millimeter CT Armor Piercing round can pierce 150 millimetres of armor at 1.5 kilometers. This is sufficient performance to defeat any current BMP-series IFV and their upgrades. This is superior to the hundredmillimeter-plus RHA at one kilometer offered by the 30×173-millimeter rounds used by the latest versions of the U.S. Army’s thirty-millimeter Stryker. 

The airburst capability of the forty-millimeter CT rounds is also superior, more than doubling the affected area versus thirtymillimeter rounds. All of this comes in a package that is around the same size and bulk as the thirty-millimeter cannons. The CT40 cannon can also hold more rounds in the ready position, around a hundred ready rounds compared to the twenty-four to twenty-five ready rounds that are possible with the Swedish fortymillimeter L/70 cannon on the CV9040, as reported by Jane’s. 

This is due to a novel rotating breech that is deployed on the CT40 cannon, as well as a linkless ammunition-feeding mechanism, made possible by the geometry of the CTA rounds. Alternative Systems The lack of take-up of 40mm as the calibre of choice was underlined in December 2021 when the US Army rejected a 40mm solution and went for the Northrop Grumman XM813 Bushmaster Chain Guns®. 

Northrop Grumman XM813 Bushmaster 30/40