DAA,
You sent the .17P dummy rounds straight to DTech at my request. If I forgot to thank you for doing this, I apologize.
Mike (DTech) was impressed with the looks of the cartridge, especially the sharp, crisp shoulders, and he told me he could see no reason that the cartridge wouldn't function in an AR. He also said he should have no problems getting a chamber reamer, as you and he have the same reamer supplier.
I haven't ordered a .17P from DTech (yet), because I currently have an unfired .223 WSSM upper and a complete .20 Tactical AR rifle that he just built for me. As soon as I recover financially from these purchases, and from a family vacation to South Dakota (can you say "coyote hunting trip"?) that begins this Saturday, I'll remedy that shortage. Mike has more than plenty work to finish, so I don't know if I can stand another long wait for one of his fabulous AR's.
Again, thanks for sending the dummy rounds.
John