In the USAAF, Medium Bomber, meant medium sized airplanes carrying medium sized bombloads over medium distances at medium altitudes. At the end of the WW2 the A-26 was considered to be capable of replacing both the B-25 and B-26 as well as the A-20, and that included the B-25 Gunship low altitude strafing missions. No A for Attack aircraft were envisioned to be needed, being replaced by fighters carrying bombs, and that persisted until Vietnam showed the problems of using supersonic jets for the Attack mission.
That I'm aware of, but what I'm interested in is what the typical minimum/maximum range for payloads were typical for bombers during the Cold War period.
For example
- Maximum Payloads: At what point would the maximum payload of a light-bomber become so large that it would no longer be considered a light-bomber and would be seen as a medium bomber? Likewise, at what point would the maximum payload of a medium-bomber become so large that it wouldn't be considered a medium-bomber and would instead be seen as a heavy-bomber?
- Typical Ranges: At what point would the range of a light bomber with payload become so low as to be unacceptable, and at what point would said range with payload increase to the point that it would be effectively be considered a medium? Likewise, at what point would the range with payload of a medium bomber become sufficiently high that it would cease to be a medium and instead be seen as a heavy bomber?
- Typical Payload: What typical payload to be carried over the specified range be such that it would be too small for an aircraft to be accepted as a light-bomber, and at what point would it be considered sufficiently large enough as to be labeled as a medium or heavy. This one seems specific to light-bombers only since the general load which were specified for mediums and heavies were around 10000 lb.
With the Cold War being a pretty lengthy period of time and debates as to exactly when it started: I figure, from the standpoint of aircraft design and development, it would probably be reasonable to divide it into the period before the Korean War; the Korean War; the period between the Korean War and the end of the Vietnam War, and; the period from the end of Vietnam to the end of the Cold War.
Off the bat, I could make some educated guesses...
From the period between WWII's end to the Korean War: It seemed that there were several light-bomber and medium-bomber designs that appear to establish some baseline figures
Light Bombers
XA-43: Initial design seemed to call for a maximum payload of 8000 lb. (some sources indicate 12000 lb.) with combat radius of 1000 nm @ 35000', 600 nm @ 10000-15000' while carrying 4000 lb. load.
XB-42: While developed in WWII, it was cancelled post-War. It was built around carrying a maximum load of 8000 lb., and hauling 2000 lb. a combat radius of 2000 statute miles (though in practice that was around 1800-1900).
XA-44: Maximum payload varies from 12000 lb. to 6000 lb. depending on source. It's unclear what the requirement called for in the basic mission.
XA-45/XB-51: Initial design seemed to call for a combat radius of 800 nm at an unspecified altitude (at least I don't remember the figures) while carrying 4000 lb. and the ability to carry larger amounts of ordinance (6400 lb. internally with 2000 lb. under each wing, or 1 x Mk-4 in the weapons bay for a 10,400 lb. maximum all-out load).
Estimates: It would appear that, with the exception of the A-26 (which, while not listed, was still operational), it would appear the desire called for a payloads ranging from 6000-12000 lb., with radius of action figures that seemed to be around 600-1000 nm while hauling around 4000 lb. of bombs.
... that said, I'm pretty sure that there are others who are more knowledgeable.