I purchased a halcyon defense 1/2-28 to 5/8-24 adapter on silencer shop and it is an absolute disaster. The 1/2-28 inner threads are perfect but the outside threads have multiple issues. First, the leading edge of the thread at the front of the adapter was mangled. Second, the 60 degree profile of the thread was incorrect. I used a comparator at 100x magnification to confirm this. Third, the minor diameter of the thread is too large, the adapter would barely start in my can before getting stuck. Finally, there is no relief on the thread at the shoulder. This makes it impossible to thread the adapter to the shoulder on the suppressor.

I had to chuck the adapter up in the lathe and cut a relief into the adapter so it would shoulder properly. I then had to chamfer the front of the adapter to fix the bad thread. And then I had to painstakingly fix the threads with a thread file. Then I had to black oxide coat the adapter to restore the finish.

I emailed SilencerShop to let them know these adapters are s--t.

We have sold tens of thousands of these in the last 5 years. We stand by our products too!

http://www.thesilencerstore.com/index.p ... ducts_id=2

Send me one and I will do a side by side and post results in this thread

We would be glad to!

Thanks

So, did a side-by-side comparison and review happen?