Hello @sdw21,
You need to explicitly un-discard the neutrino transport (since it is by default switched off) for your input to generate results. Check in the manual the use of the DISCARD card, setting any of the WHATs to “-NEUTRIE”.
To properly get the information using USDRAW of the secondary particles I advice you to take a look at this and this post. The energy and momentum are obtained through ETRACK and PTRACK, respectively, as also detailed here. I think in your mgdraw.f routine you would also need to specify the output format properly to not raise an error, at first instance i.e. by using WRITE (IODRAW, *) … .
Taking a quick look at your input it seems that the TARGET region is not well defined and you probably also don’t need two USERDUMP cards.
Cheers, hope this is helpful. Don’t hesistate to ask further questions!
Andreas