Vfourmax, you left something out. You should have inserted the word "significantly" before "loose". The difference between the two bore diameters once used was no more than a couple thousandths of an inch. And it did not affect .22 LR accuracy one iota.
Ruger is one of the world's largest firearm manufacturers. It has always employed some of the world's best designers and engineers. Their market share proves that buyers agree that these guys are not exactly clueless, regarding their firearms expertise. More than half a century ago, the Ruger engineers collectively decided it was silly, inefficient, and pointless to make two different barrel diameters for .22 LR and .22 WMR. So they used the God-given cranial resources between their ears and stopped doing it. In the ensuing half century plus, nothing negative has come out of it.
As in "N-O-T-H-I-N-G".
Perhaps if somebody on this forum points out to them the error of their ways, they might reconsider. Or maybe not.
I think that is a "barrel lottery" where the Ruger owner wins 100% of the time.
Of course, that is assuming that people on this forum do not have greater experience and technical knowledge than the entire engineering department at Ruger.
Another factor which nobody here has yet mentioned is that, since its introduction by S&W in the mid-1800s, the soft lead .22 rimfire bullet has been designed with a concave base so that, upon firing, gas pressure and inertial forces slightly enlarge bullet diameter to fill and seal the bore. A fired standard .22 rimfire bullet, while flying, is the diameter of whatever bore it was fired through, unless that bore is really, really severely worn larger. This may not be true of some of the harder specialty bullets, of course.