Converting an A2 to a flattop?

[SoDak]

I've got a bushy dissipator sitting around that I'm trying to decide if it's worth switching the A2 upper out for a flattop. My issue is that I can't decide if it's worth keeping the barrel and swapping just the upper or if I need to get an entirely new upper. What I want to do is have a rifle with a low power(1-4) scope that can be effective on coyotes out to about 250-300 yards. Can I get that out of a bushmaster barrel with good ammo? The barrel itself is a typical 1/9" twist chrome lined hbar with about 500 or so rounds through it. I'd like to get an entirely new upper, but If I could keep the barrel and just swap the upper, I'd prefer that since then I can afford a good scope.

[MMcfpd]

Swapping out the upper receiver is easily the cheapest route as you can get a stripped flattop for a little over a hundred dollars and you've already got everything else you'll need. Well, as far as parts go anyway; you'll still want to have access to at the least a receiver vise block and an armorers wrench/barrel wrench, but you may be able to borrow those.

And then you'll have a stripped A2 receiver to sell to help you recoup some of that $100+ you spent on the flattop receiver.

[SoDak]

Sounds good, although I may just buy a complete flattop since they only cost about $16 more at bravo company. Also, I can just reuse the barrel nut? I wasn't sure if I needed to get a new one or not.