i am obtaining a Glock 17T (simunition gun trainer) and i have heard that the frame will accept a standard G17/22 slide/barrel top end and thus would function as a regular pistol. but then i also got on another webpage and that poster said that the feed ramp is lower on the frame or something accomodate the off-centered simunition barrel. i'm wondering if ATF considers the training gun to be an actual firearm, and if so, is it considered a pistol because it can accept the 9mm/40/.357 SIG top ends? interesting if it does. any informaton would be appreciated. thanks.