I don't have an Umerax SA10, basically the same as the Webley Nemesis....
Added Info.... Not the same as the Webley, mine has a 1/2-20 UNF thread and the SA10 IS 14mm for Fake Suppressor's.....whaaaaatttttt...
Send it back and get something with a 1/2-20unf thread so you van put a normal Suppressor on it......
or you can buy an Adapter to convert.....PITA