I stopped and chatted with them for a bit, shot the breeze Marine Corps. style, and generally just drooled over the proposition of sending a .50 caliber round out of an AR platform rifle. Here is a photo I snapped at the GAOS in Harrisburg, Pennsylvania:

.510 Beck
Sadly, I haven't had a chance to shoot it, yet. Obviously—because I didn't make it to see them at range day. However, early reports say that it is similar to shooting a 12 gauge shotgun, but a lot more fun. Check out this video of it in action, here:
https://www.youtube.com/watch?v=Tb9L2DJlOkY
One of its intended uses is for hunting. Though, Tyrannosaurus Rex has been dead for a few years and I'm not sure what hunting application it would be for. Still, it is pretty bad ass. Personally, I can't wait to shoot one even though I may have to sell one of my kidneys on the black market to buy the ammo for it. What's your take on this beast from the Marines over at Devil Dog Arms? Would you like to take it for a joy-ride?
I shot twin 50s for just short of two years, from the front of a PBR, if a .50 is not enough. Then I think you may as well make a 20mm rifle, I mean why not, you can use it to shoot down alien spaceships.
Awe,nuts- that’s too much gun for alien spaceships! I shot one down in Roswell, NM with a wad of chewing gum slung out of a hunting sling back in then 1940’s!!