For the money you'd spend on an extension/fake can, why not fill out a Form 1 for a SBR. They allow SBRs in your home state right? I've heard from a few members that the fake can can cause accuracy problems. That isn't every one, but some have had that problem. I don't know as I have ever seen a 16" barrel for a K. I'm sure a good smith could convert a 16" barrel for a full size to K specs. But you'd end up with a lot more in that barrel swap than you would in the stamp for the SBR. YMMV.