Here is a fundamental thought:
There is absolutely no reason to purchase an oversize reamer if you don't have an immediate need to use one. Rework or repair is one thing, but we are talking about new construction best practices. To those builders who report bolts eventually wallowing out gear tower holes, I'd have to openly question their drilling technique. That wallowing can often be the result of dimensional slop built into the hole in the first place. We know that too many builders make the final full size pass through bolt holes using a common drill bit. That sorry practice is an unqualified, utterly indefensible no-no. This is sheet metal 101. Always use a reamer to make the final pass through bolt holes, close tolerance or not. There are no ifs ands or buts about it, period. If ever there was a hard and fast rule, this is it.
My personal choice of reamers is influenced by the rigid construction standards central to my former production experience. In that environment, every hole you ever drill is inspected for hole quality. As homebuilders, we don't have to be that strict with ourselves. Still, as a rule I seek as snug a bolt fit as practical. For that reason, when preparing a 3/16" bolt hole, my first choice is a .1870 reamer. If that proves too tight, I up it to .1875. For a 1/4" bolt hole, I try to use a .2490 reamer when I can get away with it but more often than not a .2495 or .2497 reamer to make the final full size pass. For the highly critical wing attach rear spar 5/16" bolts, in addition to using a bushing block which is always good practice, I prepare those holes with a .310 or .311 reamer.
I know those are relatively uncommon reamer dimensions but most builders have ready access to nominal size reamers available everywhere. At the very least, it should become second nature for all airplane builders to use a reamer for making the final full size pass through every bolt hole they ever produce.