Re: Rem700 vs. Custom action
This is a really simple discussion in my eyes.
If you already have a R700 action, then by all means use it and have a reputable gunsmith do the works.
If not, and you want to get the very best action for the least amount of dough, get a Stiller Predator with their new one-piece bolt. Now, if you are willing to spend a little more, then the choice of custom actions expands considerably. But, Stiller actions have a superb reputation and very modest cost.
Also, keep in mind that the action is a ways down the list in terms of impacting accuracy. Barrels, bullets, optics, mounts, and gunsmith choice are definitely more important than action choice.
One thing to be careful of with some custom actions is getting too tight of bolt to body fit. This will cause cycling problems in dirty environments. BAT machine known for having this problem.
PS. $4300? That's a no expense spared budget. In that case, my action choice is Defiance Machine with a picatinny rail made by them.