My apologies, I'll try to get better at this.
I'm doing a step by step install, and I just added FWE 5.04 (from a FOMOD made from the FO3Nexus download). I coc'd to Rivet City from the birthday party and went outside and Crow was there. He had the big triangle thing on him, so I killed him and it turned out to be ".44 Magnum".
I don't see anything obviously wrong with the installation, but I also don't see any obvious model for a 44 Magnum (separate from the vanilla Scoped 44 Magnum, I'd assume). Without FormID Finder or Refscope, this isn't so easy.
If you sure you installed all your mods correctly and do not forget about archiveinvalidation- then probably this is FOMM fault. Please use version 11.9 or reinstall manually all FWE assets. We have many complains on Nexus forums, and I experienced some troubles myself. Because of it- I DON'T RECOMMEND using FOMM 0.12, until it will be fixed
edit: forgot to ask, is the bashed patch and/or merged patch and/or masterupdate necessary at each step of the install, or should I be able to test basic functionality without them while installing?
The later, but after testings please do merged patch and masterupdate, and begin new game