This bit of information should be in bold in the text of the ad ... It would have save me a great deal of frustration when I received mine ... I did notice today that down in the parts check list it says the threads are at the base of the barrel like the original design (which also should be in bold) ... If it was there before I missed it, what I focused in on was that the description said to "add your favorite trigger pack and suppressor"
On the other hand, maybe in my excitement to be taking this off my wish list ... Maybe I'm the only one that has run into this problem.
So, I'm probably beating a dead horse here but ... Unless your favorite suppressor is a MP5 SD-N type suppressor, your favorite suppressor won't fit.
With the help of a machinest friend of mine, he helped me make my SWR Octane suppressor work and he's working on a SD adapter that he plans to make available as currently there isn't anyone that offers this type of adapter ... It's basically a blast chamber that the suppressor threads onto so you really can use your favorite suppressor, instead of having to lay out $6-800 PLUS the $200 for your stamp ... and wait 8-10 months to get a proprietary suppressor that won't fit anything else.
Anyway, if an MP5 SD has always been on your "wish list" ...This is a fantastic piece of equipment!
Since getting my suppressor issue work-around solved, I installed my favorite trigger pack, which includes a registered Flemming sear (so I didn't have to wait 8-10 months for a form 1 to come back to add a stock, for comfort and have ran about 900 perfect and trouble free rounds down the tube
... Every thing from cheap 115 grain to Speer 147 Gold Dot Bonded, runs perfectly! (Just don't try sub-sonic ammo because with the bleed ports it doesn't have enough energy to operate the action.
It also breaks down to fit into my laptop case so I can take it to work and slip out now and then for a nice quiet lunch!