[becky]

I think the default B-29 in IL-2 has actually the armament of the B-29 A, with four 12.7mm in the upper forward turret and no 20mm cannon in the tail whilst the B-29 had just two 12,7mm in every turret but the 20mm in the tail gunners position in the early production variants..
The B-29 B had no turrets at all.