EMT shears? Work fine on webbing like seatbelts. Buy them as EMT shears - cheap. They come in large and small - I bout a dozen last time for like $20-25 (small size)

One thing an EMT who did a real world serious test (drill with the army, everyone was in old BDUs expecting them to be cut off) - they go dull fairly fast. He said a pair was good for 2-3 pairs of pants, and then really needed to be replaced. They are cheap because they are disposable - get them contaminated, toss them