Pinchedfinger, it's been my personal experience, with every Vanguard I've owned or helped with, "they need all the help they can get."
I'm a bit of an accuracy freak, so my expectations of a rifle may be different from those you expect.
I have yet to see an off the shelf Vanguard shoot factory ammo into consistent groups under 1.5 inches at 100yds. Most of them are 2 inch rifles.
With a bit of tweaking to the trigger and bedding, and good glass, you might be able to get it to shoot consistently into 1.5 or slightly less.
If you hand load for it, maybe, and that's a big maybe, an inch.
I'm sure there is the odd "unicorn" out there, or so the owners will claim, but they're few and far between.
I don't "break in" barrels, neither do a lot of other folks, but some swear by it, with little or no proof, other than they got used to the rifle while they were "breaking in the bore."
If you do start with "cheap" Federal ammo, which really isn't all that cheap, or poor quality, and it shoots well, stick with it.
Premium ammo doesn't always shoot better than "cheap" ammo, but it usually has better bullets, with consistent powder charges.
There isn't a lot of "bullet selection" when purchasing off the self ammo, if you can find flat base, spire point bullets, your rifle will very likely shoot them well enough to hunt Deer size game with out to 300yds.