IMO a 330-size trap is a poor choice for otter unless it is fully submerged.
For fast moving otter’s a 330-size trap quite often closes on them to far back resulting in poor hip catches that don’t dispatch them quickly. My experience with the smaller 280 is that it closes faster and results in fewer, if any, poor catches. The 280 will also capture more of the incidental mink and muskrats that often trigger 330 beaver and otter sets without getting caught. Thus, it is the ultimate otter trap IMO.

I tuned my 330 triggers per some posts on here, and that helped a ton. I caught 4 muskrat in them and my otter was caught right behind the head, never made it to the second jaw.

Filed the dog to take out trigger play and chamfered the corner of the dog to reduce engagement.

You could try putting thin wire between the spread ends of the trigger. There's a lot of room in a 330 for an otter.

IMO a 330-size trap is a poor choice for otter unless it is fully submerged.
For fast moving otter’s a 330-size trap quite often closes on them to far back resulting in poor hip catches that don’t dispatch them quickly. My experience with the smaller 280 is that it closes faster and results in fewer, if any, poor catches. The 280 will also capture more of the incidental mink and muskrats that often trigger 330 beaver and otter sets without getting caught. Thus, it is the ultimate otter trap IMO.