The Boeing B-29 Superfortress entered service in 1944 with the USAAF, it was a four-engined heavy bomber which provided the Allies with a long-range strike capability for the war in the Pacific.
There were very few versions of the B-29, and only Britain and Australia operated them outside the USA. The Soviet Union also made a copy and it was manufactured by Tupolev as the TU-4.
The Superfortress was armed with up 12 x 12.7mm machine guns, mostly in remote turrets, and carried a 10,000 lb bomb load as standard, the Silverplate versions were adapted to take the 'Little Boy' and 'Fat Man' atomic bombs. B-29 'Enola Gay' of the USAAF which dropped the 'Little Boy' atomic bomb on Hiroshima
I think they did as we did which was to move to jet bombers like the Canberra. It seems strange to replace something so large with a fairly small jet, but nuclear bombs were getting a lot smaller and we were also developing Vulcans, Victors, and Valiants for the main fleet, so the B-29 had a VERY short time with the RAF - 1950 - 53.
And also a plane like that must have been very expensive to operate, plus the fact that with the jet age (as shown in Korea), it was an easy prey for the new fighters.
it was less easy prey then you might think. The B-29 could operate at extremely high altitudes, which made it difficult for even jets to reach (assuming they were being scrambled). Early in the Mig15s life, they would have a few on CAP, but when the Sabre came into the fight, it started knocking most of them from the sky... long before they could be vectored to engage B-29s.
you forget, the Mig15 didn't have an afterburner, so, like all jets of the period, it couldn't do a zoom climb from ground to max altitude (like the Mig17 could). Now, while the rate of climb was better then anything the US had (even the Sabre), what ultimately did it in was the lack of pilot skill. Most of the Sabre pilots to arrive in Korea first were WW2 vets in Mustangs... so they had the experience to deal with the Mig.
That said, the B-29 did have issues when the Mig15 first appeared, but that was almost always with aircraft that were already at altitude and could 'jump' it, knocking out any F-80s in the area, and then proceed to wipe out the bombers. But, like all jets, they couldn't do it forever, especially with the Russian pilots that flew some of them (they HAD to RTB before they hit bingo fuel)
That said, the B-29 did have issues when the Mig15 first appeared, but that was almost always with aircraft that were already at altitude and could 'jump' it, knocking out any F-80s in the area, and then proceed to wipe out the bombers. But, like all jets, they couldn't do it forever, especially with the Russian pilots that flew some of them (they HAD to RTB before they hit bingo fuel)