Why do you think a Savage action takes you out of it? If you shot Butner, you shot against David Hodges, who uses Savage actions in both his light & heavy gun, and probably won *something* at the match you shot. He usually does. Of course, he's a master machinist & has been through them...
Hard to say where to start. Think about what we ask an action to do. (1) hold the barrel, (2) provide ignition, (3) bed (fasten) the barreled action to the stock, (4) position the scope. Further subpoints at each number. People will come on here & stay, "Oh, it isn't true" & have no idea of what "trueness" accomplishes. Actually, no one knows, in the sense of having a statistical analysis of hard data so you can quantify what matters & how much.
Are there better actions than a Savage, Probably, depends on just how good yours is -- one of the best they ever made, or one of the worst? To take all the measurements would cost as much as doing all the work, and you still wouldn't know what to correlate the numbers to, in terms of target performance.
What does all this mean? It means, "how much money do you have to spend?" If you take that one small group at 1K & decide, "My action's OK (& likely it is), the biggest improvement will come from getting good barrels.
So let's assume you're starting with a good action, stock, scope, and rests.
Shannon Lowman, who you may have also shot against at Butner, bought 15-16 barrels for his run at 1K Shooter of the Year last year. Believe he felt that 3 were superior. He shot 50-60 matches. Shannon believed that towards the end of the year, his 3 superior barrels had lost their edge.The woman who won SOY bought around 25 barrels, and made more matches.
Beginning to see a correlation?
BTW, these were both 6mm Dashers. .30s last longer (for good or ill). .30 Bullets cost more. .30s are probably harder to shoot. Another correlation... And NOBODY shoots a .30 at 600 yards -- except Sam Hall just investigated getting one for this year...
Next in the performance improvement will be bullets. Bullets (1) your barrel likes, and (2) that you can get in repeatable, consistent quantities. Well, forget (2) in 2013...
Farther down is powder & primers & rests & everything else. At some point, it all matters, everything counts when you're making a run at winning a lot.
Go to a 600 yard match -- Piedmont closest to you? Watch & listen, esp. to the old-timers who have done a lot of winning, even if they're not winning just now. Winning "right now" involves that barrel & bullets & etc. Controllable only if you have enough money to pitch a ho-hum barrel. Otherwise, like most of us, you shoot it for a few years & take whatever meager wins it offers, until you can afford another. The old guys will have been through that cycle & understand the "luck" (somewhat equivalent with money) element.
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How long a barrel? I'm a 1K, not a 600 yard shooter, but believe most would say 28 inches. With a plain 6 BR, 26 would probably see you home, but why? To save a few bucks? Well, if the money's that dear, R.G. Robinett (for one) would allow that he never saw any need for a 6BR barrel beyond 26 inches, & Randy has good reason to know. I'd still go for 28 inches, finished length. (But I'd go to 27 if it saved me $30 a barrel...)