anyone here ever shoot one of these?  just wondering about ammo and component availability, how they shoot, etc.  recently saw in the american rifleman where the coast guard is going to a large caliber upper as well. seems like using something like a .454 casull would be feasible (is it a rimmed cartirdge?).  anyone know of an upper in .454?  

Hello.....ben shooting one of these for a few months now, excellent cartridge, good penetration on deer and adequate accuracy. probably the ultimate foul weather rifle with Aimpoint ML. You'll love it.

it looks to be the next upper for me.  lots of punch and power.  any reloading data around for it yet?  also, have you experienced any problems with your lower reciever - more wear, etc.? cabelas has the uppers and ammo and i
have seen some sources on the internet.  any preferences on dealers?

No problems with my lower, only 200 or so rounds through mine. A local rep that I know has many hundreds of demo rounds through his and gun is tight and accurate. The factory will give you loading data if you purchase the dies, I have reloaded 130+ rounds, the balance has been factory 325 and 334gr ammo. No preference on dealers, but make SURE you use mounts that would also work with a 12 GA, the only non-failure mount I have found so far is the Aimpoint QRP. Make sure it is not the QRW(weaver). SWFA.com has them. Good shooting.

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!

The experts on the .50 subject (especially beowolf) are these folks:

http://www.forceten-gemnitch.com