Love mine, so far at least - I'm a lazy son of a bitch and haven't been to the range in six months [>Q]. Oh well, hopefully I'll get to experience the "love taps (pounding??)" on sunday... BTW: If you intend to handload your own, it would behoove you to measure your brass if you order it unfired. I got 100 empty cases and later found (after loading all of them) that they were either AT max length or .001"-.002" over max. It really sucked - half would chamber just fine, and the other half would get stuck with about 1/8" of bolt carrier travel left to go. I had to pull each round and then trim it to length. Was a real bitch finding a trimmer that could handle cases like that. I eventually settled on the Lyman trimmer, with a .50AE pilot, and their extra large deburring tool (normal deburring tools won't work either). As far as availability: I ordered my stuff from Impact Guns and the upper from Cabela's. At the time everything was backordered but it showed up soon enough. As for the .454 Casull: yes, it is a rimmed catridge, and from what I remember from a thread with Tony Rumore, king of the big bore AR's: the .454 has too large a head size and too high of a chamber pressure to be used in the AR15. Too bad[V]... The .50 Beowulf has ballistics almost identical to the new .500 S&W, which is the undisputed heavyweight champion of the world as far as handgun power is concerned. Oh well - enough of my drunken rambling! Get your upper already!