What you have is the crimp that is built into the head of the case around the primer pocket its not part of the primer it will need to be removed, once you do it for that lot of 500 you wont need to do them again. This is what I use and works in your press it will come with a large rifle and small rifle swage you would use the small rifle swage for your 223 . > http://www.midwayusa.com/viewproduct..._campaign=9315
you can get a reamer to use also some like this better you will have to see what you like
And yes being the AR15 I would plan on crimping the case around the bullet , I have the Lee factory crimp die so far I like it.