I have a bushy A3 with 20" barrel, went out and bought a 16" upper and change the two out. Shoot one type of optic off the 20", eotech off the other.

I notice on the bushmaster site that some uppers are sold with bolts, some you have the option of, or not.

So here's my question: What's the tradeoff of changing the uppers out but using the same bolt/and bolt carrier? Is it accuracy, safety, or does it not matter? As long as the two uppers get shot about the same, should I care?

My only frame of reference is in the army we try to have equal wear on the MG barrels, and don't match bolts to each barrel--is this a sales technique to sell off extra bolts every time someone buys a new upper?

Thanks.

some of teh high dollar barrel makers sell ya a bolt that has been match ed to that barrel.  it is chambered to minimum specs to that bolt.  for jus a regular barrel i would not buy a barrel with a matched bolt.  i just check the headspace with the new barrel to the old bolt.  most of the time i think its just hype.  it does not matter really if ya have headspace guages