Vince wrote:
Also under consideration is a redesign of the V-22’s nose to accommodate
a chin gun, Birkholz said. “It’s all do-able,” he said. “It’s just
expensive.”
http://www.nationaldefensemagazine.o.../V-22_Aims.htm

it wasn't doable

you can hang it on the belly at the center of lift,
that is where they put the cargo hook
http://www.defenseindustrydaily.com/...ng_M777_lg.jpg

Delete the hook. Any mission that the V-22 can use the hook for the
H-53 series can do better.

For any mission that doesn't include a sling load the V-22 flies faster,
higher and further.

-HJC