Foundry Rumble is an explosive awesome pit of karnage, spawn ring rumble pit of destruction. 150% strength, xtra points awarded 4 assassinations,beatdowns,and splatters 16 player.
Brute Choppers are also present on the map.
(A few changes since this pic, but basically the same)

Be sure to grab the gametype also. Has BR start with Random secondary, plus all the settings.
http://www.bungie.net/forums/posts.aspx?h3fileid=38668535