I am a HUGE Ruger fan and have at least a dozen in various calibers and configurations. I once wanted a 458 mag and it was listed in their catalog, but when my gun dealer looked all over the country for one, he was never able to find one in almost a years time ( this was in the mid 90's ). I then told him heck with it and ordered a winchester on wednesday and had it friday.
I always heard they tooled up and made a lot of a particular caliber, then switch their tooling and make another gun/caliber combo. One plant made rifles, while another made handguns.
I am still a HUGE Ruger fan though and when I am the mood for a new gun, I ALWAYS look to see if Ruger makes it first, and only look elsewhere when they don't.