For the Vectis, You'll have to cut the plastic muzzle break back until at least .5 inches of the barrel sticks out. The threads are 1/2 x 20, I would pair it up with a .25 Sumo 1/2 x 20 S9. We are not responsible for damages to your airgun if you decide to procede with this modification.
https://donnyfl.com/collections/ldc/products/1-5-x-6-5-inch-sumo?variant=37719183748
How to video at 14 minutes.