I'll take a stab at this: Since the Remmy 700 is pretty much the small block chevy of the bolt action gun world the bulk of what I'm describing applies to it. It can apply to other actions as well.
Many smiths offer the "meat and potatoes" of tuning up an action. The baseline of this operation is the tune up the face of the receiver ring, make a clean up pass on the internal receiver ring threads, skim cut the locking lug surfaces of the receiver, and take a pass off the lug surfaces of the bolt.
From there it gets more involved, a guy may want the bolt face cleaned up and/or a bushing installed to better captivate the rim of the case. He may want a different extractor installed. The scope mount holes can be opened up to a larger thread pitch for better strength/retention of the optics. Helical fluting of a bolt is an option I provide, a new fire control system with a fitted shroud that alters the action from a partial cock on open/close to a full cock on open only. This is nice to have when shooting from a bench and it improves the overall "warm and fuzzy" feel a guy gets when running his gun.
Pinning the recoil lug to the receiver so that it indexes in the same place each time is another option I offer. I DESPISE those tools that use the front guard screw to register the lug.
TIG welding the handle to the bolt body is another feature I include with this as well as adding an external bolt release.
Thats what I can offer. NOT trying to be salesman here but if you visit my site I have a page called "process" that illustrates some of this a little more.
For anyone reading this, please pay attention to this part. IF you like it and want all this done understand that none of it is cheap and dollar for dollar you will be much further along if you sell that Remmy action/rifle and use it and the money you were going to pay a higher end smith to just buy a custom receiver because your going to be right in the price range anyway. Figure a Remmy action these days runs about $450 in today's market. I charge $800 for parts/labor. You can buy (as an example) a fully decked out Defiance Machine action for the same price and have ten times the gun when your done.
I offer this blueprinting service because I can do it, but truth be told I'd rather see you have better parts to start with than pay out the nose to turn a pigs ear into a silk purse.
Hope that answered your question and puts things in perspective.
All the best,
Chad.
