Bomb Practice BDU-42/B question.

[pzgr40]

I just cut this "Bomb Practice BDU-42/B". However, I have the idea parts are missing. The screw in the base is obvious, but what was placed under the blue cap? A smoke or spotting charge?
Who can help me on a drawing?
Thanks in advance,
Regards, DJH

 

[US-Subs]

DJ,
my books are currently floating around on the Atlantic (hopefully), but what I've got electronic suggests that what you see is what you get. No internal drawing, but:

"This is a fluted sphere consisting of a plastic case filled with inert zinc die casting. The fuze well is empty and closed with a plastic cap."​

 

[pzgr40]

Thanks US-Subs. However , why this cup in the center ? Is there also a type that has something in there? I know there is a same type of practice bomb that has a red cap (BLU-70, see big ordnance forum) instead of Blue. Any difference between the two?
Regards , DJH

 

[US-Subs]

DJ,
not "the same sort of practice bomb". The BLU-70 used the same outer body as the BDU, but was an incendiary submunition, using the M219E1 fuze and .8 lbs of incendiary mixture (powdered zinc, barium nitrate, lead dioxide, benzene, polystyrene and thixathol as a dispersant). Developed in the late 60s it had a short life. The one belonging to BO is the only one I've seen in person.

 

[US-Subs]

DJ,
looking again at the photo and my own post, I would suggest that the BDU was made from remnants of the BLU program, using up remaining scraps instead of building a new BDU body. I think that this would perhaps be a better answer for your questions. JO