Unless Wart On have designed it out - nothing would surprise me - the Hawk inc. 100 series, as developed by Kingston / Dunsfold, could happily carry a 30mm Aden on the centreline, which worked jolly well.
I am hardly a supporter of BAe, having left voluntarily as internal politics sickened me, but I can say they price their aircraft relatively honestly including 'product support' -
a very significant part of the bill indeed, which at the time - I don't know about now - the Americans never did, quoting bare airframe prices.
As far as guns go, of course the Hawk 200 has 2 x 27mm Mausers carried internally.
http://i234.photobucket.com/albums/e...g?t=1199221552[/IMG]
http://i234.photobucket.com/albums/e...bscannon-1.jpg
When the Swiss went for the Hawk, they specified a link collection system had to be designed & fitted; apparently it's fine to fire cannon shells at people, but considered rude to litter their place up with links in the process.
(Yes I do know it was for their test ranges, and in the end they sold them to go back to what they do best - standing around making chocolate while pretending not to be aligned with anyone )...