Originally Posted by Peregrino

Hmmm. You might want to take this question back to AR15.com where you came from; however, to get you started - anything is at least remotely possible. If you know what you're doing and use proper proceedures, it is possible to do what you're asking. That isn't saying I think it's a good idea. Given that the barrel blank used to build my 300WM cost $500 (and that was the REALLY good buddy price) and I expect to have to replace it at around 1500 rounds, I doubt seriously that you could convince me to shoot AP ammo in it. And I'm pretty sure anyone else with a quality rifle will tell you the same thing.