For the Sortie you will need this adapter. Warning, suppressors do not work well on Hatsan's line up of semi-auto guns. It will disrupt the magazine index and will not index properly. Use this adapter only if you plan to single load.
I recommend the Tatsu .25 1/2x20 for the Sortie.
https://donnyfl.com/collections/ldc/products/1-6-x-4-25-inches-tatsu?variant=10542670676011
We have figured out why the gun does not cycle properly when moderated. The larger orifice on the stock endcap allows for the correct back pressure to send the bolt rearward (spring assisted return). When the adapter is installed the air restriction increases the back pressure which effects the spring's ability to return the bolt (there's too much compression). I went to the hardware and picked up a few springs and found one that would run the gun. After trimming off a few coils I was able to tune the spring with the adapter installed. Works like a charm.