this is the hunting section...

anyway you can pick another weapon skill when you board the collector ship (its like 2 missions after you do the mission on Horizon) as a vanguard you can pick between assault rifles or sniper rifles, or you could specialize in shotguns which gives you the Claymore heavy shotgun that you see Grunt using. i'd go with the sniper rifle, it gives you more options at attacking at both long and short ranges. besides, the auto shotgun you get on samara's recruitment mission has a higher ammo count/fire rate, it comes down to about 3 shots for every 1 from the claymore.