Do new inners come with a cunningly prepared end? If they do, I didn't know that.
The decent single-ended inners are cut electrically, leaving a very neat little blob of melted metal on the end, which threads though brakes and outers as easily as is possible, and which is immune to loose strands of wire.
Don't ever get the cheap double-ended Road/MTB brake cables, that require you to cut the wrong nipple off, and don't cut any excess off until after you've finished fitting the cable.
If you cut the end, even with a good cutter or the application of solder or superglue, what you end up with will be less neat and harder to thread.