Lots of surplus ammo out there. I have had very good luck with West German DAG.
Its de-linked MG ammo, but the FMJ bullet is designed from a nickel alloy that really comes apart well in pigs. Military FMJ, unlike commercial FMJ, is designed to fragment in fluid mediums (like us) and the West Germans did a good job making a more lethal bullet than our m118 load (I guess since the party was going to be at their place, they took a little more interest...)
Its accurate enough in my bolt guns to 600 yards, so its a good plinking/hunting load. You can find it online for $250 per 500 or so.