If you have dedicated 45 Win Mag dies, then no, you wouldn't be able to crimp the ACP cases. Just as you couldn't crimp 38 Special cases with dedicated 357 Mag dies. Should do just fine reloading the Win Mag using ACP dies, just by backing the dies up a bit to proper height for crimping, seating, etc.. Anymore, I'm not even sure anyone makes dedicated dies like this, as they're generally advertised as 44 Spl/Mag, 38 Spl/357 Mag, etc.. As Pinecone said, 45 LC is another matter entirely, as there's different body dimensions involved. But again, 45 LC to load 454 Casull, no problem, since they share body diameters, differing only in length.