This is from page twenty of LHTR pdf file
Strategic Bombing Raids: a bomber can make an economic attack against an enemy industrial
complex. During the opening fire step of combat, bombers that survive any antiaircraft
fire may attack the industrial complex. Roll one die for each surviving bomber. The
opponent must surrender that many IPCs to the bank. The maximum combined damage inflicted in one turn by all strategic bombing raids on one industrial complex and any rocket attack on the same industrial complex is the territory’s income value.
Italics mine.
This from the out of box rules page 28:
Special Abilities
Strategic Bombing Raids: A bomber can make an economic attack against an enemy industrial complex.
During the opening fire step of combat, bombers that survive any antiaircraft fire may attack the industrial complex. Roll one die for each surviving bomber (the maximum each bomber can inflict is the territory’s income value). The opponent must surrender that many IPCs to the bank.
Weapons Development—Heavy Bombers: If you have the Heavy Bombers development, all your
bombers roll two dice on an attack instead of one. That means each bomber can score 2 hits in a regular attack, or inflict two dice of IPC loss in a strategic bombing raid. (It still cannot inflict more loss than the territory’s income value.)
Italics and bold mine.
If you are playing out of the box SBRs can do some hurt. Not as much hurt in “tourney” rules. Those are the out of box rules pdf from the Avalon Hill website. I think those are the latest LHTRs but it is from the link to the pdf version in the sticky thread. I guess that leaves the question of if in LHTR by turn they mean UK’s move or R thru US moves. My earlier post while not quite wrong is misprecise.