On the one hand I can see your point. On the other I want the SOB to run out of ammo faster, so I'd say in general I'm against it. It's still got 36 guns all aiming for 1 players's pipper (not all at once, but still, 36-frikkin-guns), even if some of them staggered, it would still be way more lethal than it ever was in real life.
I think the problem with bombers isn't their guns, at the moment. I think the problem with bombers is their constant 300mph speeds and the fact that they outrun most fighters in this game. If we impose stronger fuel burn on bombers (only bombers, like fighters still have 2x but bombers have 4x or 6x) then they HAVE to conserve gas, which means cruising, which returns bombers to a more historical footing.
If bombers cruise fighters actually become a threat, because they are now travelling much faster. In this situation bombers would NEED 36-frikking-guns.
So I say the problem is not the guns, but the "ludicrous speed!" setting they all fly at 100% of the time. Hell the only time any bomber EVER throttles back is to stay in formation or to land (if they even bother to do either).