B-17G-5-BO vs B-17G-20-BO

[RAF_Loke]

Can someone tell me the difference between the 5-BO and the 20-BO?

[JMSmith]

15-BO

[Jarink]

I think the main difference would be the waist gun positions. I know some of the early G blocks still had the unstaggered open windows as seen on the Fs, though I'm not positive when that changed to staggered enclosed positions.

The only thing I'm positive about with the early Gs is that the G-1-BOs did not have cheek guns, which were added on the G-5-BO.

I might have to try and look this up when I get home.