I bought a barreled upper today but it didn't have a bolt and carrier.  I paid 200.  It is an A1 upper with a free floating handguard, standard front sight base and pencil barrel.  I hope I didn't get taken.  Anyway It didn't come with a bolt and carrier and I was wondering where the best source for a bolt and carrier complete was for a plinker rifle.  As always reliability is the biggest factor for me.  Is switching a bolt and carrier back and forth a bad idea?  Thanks for your knowledge.
           

At the very least, each barrel should have its own bolt.  I have to recomend Bravo Company and thier m16 bolt and carrier cuz thats all I use.  Really, theres not a whole lot of difference in any of the manufacturers unless you buy a super-secret ninja colt bolt that is impervious to magic spells and MP tested.  Other manufacturers are proving by MP testing that the price of a colt bolt is overrated.  BC should have CMT MP tested bolts and carriers.  BravoCompany USA

You didn't get taken doesn't sound like. (without seeing the upper and so forth)

The chances of having problems with a new bolt and carrier are very very small.