For optimum accuracy combined with reliability you want one one-thousandth clearance between the bushing and the slide and the barrel and the bushing.
If memory serves me correctly, five one-thousandths total is the max on US government specs.
Check out Evolution Gun Works. They'll make you a custom bushing for under $25. Tolerances will probably be so tight you'll have to take some 400 grit sandpaper to it to make it fit.
While you are at it, order an EGW oversized slide stop. Normal wear will reduce the quality of the lockup between slide stop, slide and barrel. The oversized slide stop will take up as much as .004 of that slop.
Yeah, get a bushing. Costs $25 shipped. It makes your gun more accurate. Cheapest way there is to reduce groups from five inches to two.
Just be prepared to spend two to four hours making it fit with sandpaper in one hand and a finger jammed up a bushing in the other.
DO NOT RESORT TO SHORTCUTS IN SIZING THE BUSHING.
Do it right and it will pay off. Take a shortcut, like attach it to a drill and you threw away $25.