I just learned of this bug today to do with 50 MG incendiary rounds, if you have too many rounds in your inventory it may cause crash's
Quote from Fallout New Vegas wiki
If incendiary rounds are added (in high amounts) through console it may crash/freeze the game on PC. end Quote
See bottom of page under bugs, see link below
LinkBefore I was given myself 500 rounds 50 MG incendiary rounds and had crashes and freezes all the time, I'm using the tgm cheat and well carry 25 rounds only for now on, yes I know tgm gives you unlimited ammo, or it always stays at the number of rounds in your inventory!..
[Edited by Hard8, 11/25/2010 8:08:12 AM]