I wouldn't waste the money to have a gunsmith do that. Could void your warranty so go shoot it first. Make sure it is 100% first. A couple hundred rounds will smooth it out.
Bushmaster is considered an average comspec AR.
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together.
You'll remember the quality of a gun long after you forget how much you paid for it.
US Army 1966-69, VFW Life Member, Retired Geek