I will preface my post by asking that you take my comments as nothing more, and nothing less than the sum of 25+ years of ranting-reflections by a self-diagnosed, and proudly admitted obsessive-compulsive perfectionist. (Stops to tap the keyboard 3 times). Yeah...I have issues! Got a couch anyone?! My name is Geno. I am a perfectionhaulic. (Taps the keyboard 3 times for good luck).
The best example of a rifle that I "tweaked" was my M700V in 6mm Rem. With factory loads, and a Tasco fixed-power 10X scope, I was able to bench groups of 0.75ish all day with factory ammo.
One day as I was at my Uncle Dave's 1,000 yard range, he was working up some hand loads with me. He thought we could easily hit 0.5 groups at 100 yards. We worked up some 95 grain Nosler Partitian loads at well over max-load, and seated the projectiles into the lands. We switched out the scope for my Redfield 6-18 Accu-Trac, mounted it in dual-dovetail Leupolds bases and rings, and expoxied them on. Can you say secure?! We (he) also set the trigger much lower…around 2.5 pounds…not creep, nice and crisp.
The first handloads printed 3/8 inch at 100 yards! My uncle was floored and commenced to nag me about selling him the rifle! As we continued to sight the rifles in for the pending deer season, he told me that most rifles can hold reasonably the same size group at 300 yards as what it prints at 100 yards, but that most fellas just don't have enough magnification for the job. Sure enough, the rifle was grouping consistent 3/8" groups to 300 yards (so long as I did my part). My uncles factory stock, Wea Mark V in .300 Wea Mag was holding consistent groups of 0.25" at 100 yards, and out to 300 yards (when he did his part). He was using a Leupold 6.5-20 Vari-X III.
What I learned from that day, and from tinkering obsessively for the next 25 years is that the barrel weight means not a whole lot. The trigger, the glass and good handloads are where one gets the most bang for the buck. Now I don't know what power scope you are using, but I bet you can cut those factory load groups by 25% or more if you tried a 36X scope for the day just for "testing" purposes (not for hunting). Borrow one from someone you know.
Over the past 25+ years, I have had an informal competition between me and Weathery, Inc. Any Weatherby rifle that I bought, I made a photocopy of the factory target, then set about setting the trigger lighter and more crisp, and working up the rifle's best load. Of course I always used custom dies. Once I achieve that goal of beating Weatherby's machine-tested target, I would send the target and a thank-you letter to Mr. Weatherby. He always took the time to thank me in writing and to congratulate me.
My thoughts for accuracy always turn to getting up close and personal with my target. If the trigger ain't good, it ain't a trigger; it’s just a metal stick. A factory trigger on a hunting rifle is sufficient if lowered and tuned. Have the bore checked. The critical area is the first about 3 or 4 inches of barrel (rifling and lands). If the barrel is rough there, (and carbon steel barrels can take hundreds of round to break-in), you loose a lot of accuracy. If it's rough, have it lapped. I lap my own.
Get some custom dies. Fire 3 factory rounds, and send the empty brass to Lyman, or Lee and have a custom set of collet dies made (neck resize only). Use the best powders, projectiles, brass and primers you can find. Weigh and separate all of these. Mark the cartridges' weight on them with a Sharpie. I even checked by projectiles for irregularities. I use Match grade primers. Get the best, most stable rings and bases you can, and epoxy them on and you will have zero shift potential.
In sum, you have a factory set rifle that is at 1 MOA. I'd bet it's a lot better than that without anything more than a trigger job, custom dies, hand load and check the barrel's smoothness. The balance (IMHO) goes to tuning the hand loads to that barrel for its preferred load. Anyhow, that's one obsessive-compulsive reloader's very humble opinion.
To me, point-of-rationality is key. I want the most for the least money. Save the fancy stuff (action blue printing, etc) for when you eventually have to re-barrel. Good luck and let us know what you decide. By the way, if 1 MOA isn’t good enough for you, you too might be obsessive-compulsive. (Taps the keyboard three more times for good luck).
Edit to add, a couple of other tricks I have used with my bigger magnum rifles with synthetic stocks (they are slippery) is to apply skateboard tape to the grip area on the stock for consistent grip and better trigger pulls. I also have applied foam rubber pipe insulation to the stock's comb where I rest my cheek to facilitate a really solid and consistent cheek-weld. Lastly, consider a Williams' muzzle brake to reduce recoil and enhance controllability. The sky is the limit on hunting rifles-tried-to-become target rifles. IMHO, 1 MOA is more than sufficient for hunting to 500 yards. But hey, tinkering is fun! (Taps 3 keyboard more times).
Geno
