"Custom" does not always you get custom results.
I have Customs, 700s, Savage, A bolts with Brux, Krieger, Hart, Lilja, Shilen, X Caliber, Pac Nor, Schneider, and Pence barrels, hard to tell the difference in accuracy with platforms being the same stock and scope. Ever seen a Ruger Tang safety and Mark II shoot 3/8" groups(and less) constantly with a custom barrel? Not too difficult to accomplish!
I like to test what the "talking heads" are spouting as being the gospel truth because so much of it is their ego, marketing, or just regurgitating popular BS. At one time, all I had was one type of custom action or another, a best friend had to die and leave me his Parker Hale and Ruger Tang safety with custom barrels to bring me back down to the Truth.
The issue of Pride of ownership is much different from a guy who is trying to achieve super accuracy with a limited budget.
The biggest issue chasing accuracy is learning to "Tune" hand loads for that particular barrel's harmonics. The issue of tuning a load is of major importance relating to chasing 3/8" and less accuracy attaining amazing accuracy with factory rifles at 500-600 yards.
Many new guys think that they can just buy accuracy, and many get disappointed, but they do have a rifle/scope to be proud of.
I have quite a few Remingtons. When the new barrel is installed, I go with a custom recoil lug .250 in thickness. If I feel they are acting up a little, I change the firing pin spring. Bed them in a SOLID stock, I prefer laminate, bed action, free float, top-of-the-line trigger, Muzzle break, and Free float magazine box. Having done this, everyone shoots tiny, tiny groups without exception. When hunting season is over, I will have the bolt handle timed. For some of the 700, the Mag well is opened up to accept a much longer Wyatts mag box, and the 7 STWs all get the 4.000" Wyatts mag box. I have thought of upgrading the firing pin to better lock time, but the chances of an improvement in accuracy is little to none.
Concerning the Remington 700s, there was a run of screws that were too long for the Remington front scope base. If the screw touches the threads on the barrel, that barrel will never shoot extremely well. So, when you install a scope base or rail on a Rem 700, tighten down the screw over the barrel tenon, then remove the screw, and look at the bottom of the screw. if you see indentions or the blueing mashed off the center or edge of the screw, then look down in the screw hole at the barrel tenon, you will see the threads flattened if the scope base/rail screw has dug into the barrel threads.
Regarding truing Rem 700s, I have two 40xs that I have had trued by Greg Tannel, they do not shoot any better than the non-trued 700s, same stocks, the same brand of barrels, same reamers used, and another project to compare.
I would never true another Remington 700 action, I consider it money down a rat hole, buy a top-of-the-line Custom action if you are shooting competition. True every Win model 70, especially the Pre 64.
There is so much Lying & ignorant BS out there, it is just sickening. For me and mine, when a barrel starts shooting 1/2", it is on its way out or adjustments are to be made. 3/4" is unacceptable, something is amuck!
If a guy had the intention of really wanting to reload and shoot tiny groups, he should invest the money to get set up to reload at the rifle range. Changes in primers, bullet choice, neck tension, powder charge, and seating depth are done on the spot, while the barrel is cooling. After a while, you develop an "instinct" of what is needed. I started reloading at the rifle range in 1984 at Registered Benchrest matches and adapted the same for varmint and big game rifles. Folks at the rifle range, are mentored in reloading skills, it is very, very contagious to say the least. You are teaching HOPE to guys that only have the funds for factory rifles, and they can be tuned to an amazing level of accuracy.