I do my own - a Savage is easier to deal with because the bolt has a floating head which eliminates the need to sleeve the bolt or to do much of anything to it, and the receiver is round so it is easy to bed although some care has to be taken with the rear pillar.
I true the front face of the receiver to the bolt bore, machine a stub to use for truing the face of the barrel nut, use a competition recoil lug from Sharp Shooter Supply, dual pillar bed the receiver to the stock (I prefer wood or laminated stocks), install the barrel using go and no-go gages, and they shoot into a half MOA or smaller with the right loads.
That said, it does take an understanding of receiver/bore geometry, some skill with a lathe, the right tooling, and some practice to get it right. I've not messed with bolt timing. I lube the cocking and locking surfaces with a tiny bit of Lucas #2 red and sticky (or something like that) and they work just fine.
You can change barrels on a Savage with out doing anything to the receiver or even needing a lathe. Barrel vise, barrel nut wrench, go/no-go gages and you're good to go.
I do the little extra receiver work but I'm not sure how much good it does on a Savage with the floating bolt head and barrel nut. I've never been able to do a good comparative test to quantify the improvement, if any. There are Savages that shoot bug holes that have been trued and Savages that shoot bug holes that haven't been trued. You pick your pony and take your ride.
I have seen Savages shoot a "lot" better than factory with just a simple barrel swap. For all their reputation for accuracy, I've seen more barrels with chatter marks and other ugliness in Savages than any other brand. They often shoot reasonably well even with the chatter marks but they can be a bear to get clean.
I think if gun writers worried less about making the manufacturer's happy and published bore pictures (chamber, crown, and the worst places inbetween) of every rifle they reviewed, the industry would see a huge improvement in bore quality almost overnight. Alas, I think most gun writers wouldn't have a clue what they were looking at if they did take the pictures.
Savage barrel quality can range from superb to downright ugly. Talking about ugly, this is a picture of the barrel I took off my Savage Model 10 .243Win:
On the other hand, I have a new Savage 112BVSS in 7mmMag that has an absolutely georgeous bore and throat. This is the throat after 30 rounds:
Factory rifles just don't get much better than that. The crown was a little rough but that was easy to fix. With receiver truing, a new crown, and epoxy pillar bedding it shoots 1/3 MOA or less with handloads.