My rule of thumb is the more mag you want the better the scope should be-ie the more you have to spend. I can't plug any absolute values in but if I'm going to buy a scope with mag of 18x or above-it has to be good-say Vortex Razor good for example-at least for me anyway.
Personally for me-a new barrel gets a new bolt. I've never really experienced a bolt making a differance in accuracty personally. Don't think I ever read about it either actually. I'd probably get another Toolcraft.
Nice grab-they gone. I have the 24" (and a 22" that I haven't shot yet) and am amazed at how accurate it is with Hornady ELD 140gr. It's actually sub moa even on bad days for me-which is about 1/2 the time.
So you're saying an upper/lower set (stripped) and you build it up? Heat sink thingy on the barrel? I'm a little skeptical on the cooling fins-I need to see how they interface with the barrel.