Yeah, your AceTech has the pistol adapter in it.
Don't screw it the normal direction... You'll tighten it. It screws the opposite way off.
Then you'll have M14 thread inside the AceTech to match your barrel.
If you intend to use the tracer though, you'll either need an outer Barrel extension. Or shorter inner.
Patrol base have just had the Slong barrel extensions in. They seem nice and cheap
http://www.patrolbase.co.uk/new-products/Slong-Airsoft