The adapter as in the original version has two fatal flaws. The threading on the inside of the barrel was not threading, rather circular parallel cut ribs. The threading on the pistol side of the adapter would force the adapter to cant off the main axis. The second flaw was the moat like recess that would cause the thread adapter to have the middle ridge extend past the end of the barrel. The barrel on the pistol was flush with the slide, so the extension on the barrel would slam against the slide and snap the adapter after a few shots.

The changes I made was to remove the middle ring that extends out radially, and to remove the threading on the pistols ide of the adapter to make it a smooth push to fit.

It has worked well so far, and feels quite solid, while still being easy to get on and off, and has the tracer unit thread on smoothly.