NEFP help

Hello,

I'm trying to propel the osmium parts (flak and the radiation plate) with a nuke. None of the shrapnel seems to hit. It's hard to tell because I can't see anything besides the flash of light. I manually detonated (the nuke) from many ranges, 100m-5 km, and the missile uses direct guidance. I got it to work once, with the third design, but it was an accident.

www.youtube.com/watch?v=uMAwttgSGTE

In this video he detonates the TNT, rather than the nuke itself.

- does it matter what I detonate?
- what yield should I start with?
- what osmium fragments should I start with?
- does the position of the flak relative to the nuke change anything?
- if I use armor instead of flak fragments, does it turn into plasma and expand or does it shoot the whole plate as one unit?

Thanks,