You certainly can bring back rifles and bayonets. However, some liberal douchebags and ignorant commanders who won't read the regs will tell you otherwise. If it was purchased from a local, it is not technically a war trophy and can be imported with the correct customs red tape if you plan months ahead. It's easier to get it through as a war trophy if you have a commander that doesn't believe everything is an illegal war trophy. Believe me, I have gotten both sides of this briefing enough times to make me sick.
In reality, the same general rules were in place in WW2. They were just mostly ignored.
I own firearms not to fight against my government, but to ensure I will not have to.