I don't know why the Ruger #1, but I have learned to love a single shot.
I started rifle deer hunting with a BAR in .270 Winchester, a gift from my father, when I was sixteen or so. He has been shooting the same in .30-06 Springfield since before I was born. I would not have wanted anything else than a semi back then. Mine is an excellent hunting rifle.
Then, we were invited to a muzzleloader only hunt. The first year, I went just to run for the older guys, not wanting anything to do with that kind of stovepipe. Their successes convinced me that I should reevaluate my appreciation of the tool and the hunt it allowed. I was then in my early twenties.
When I was in my last year in school, my father took me to the gunshop in the city where he had bought his Encore muzzleloader a few years before. I bough the same gun, with a little help from my dad... I never thought I would enjoy single shot hunting so much. Many years later, a few years ago, the same gun shop had Encore .30-06 Springfield barrels in stock (this never happens here) and announced a special. I went and bought one, scoped it with a Leupold. I could not find a forearm matching the original camo stock for the life of me. I could not stand two different parts, a black forearm being all I could get for the riffle barrel. I bought the pro black stock with the thumb hole, unsure if I would like it.
It is, by far, my most pleasant rifle to shoot. It is simple, robust, 26" barreled but easily maneuverable, stainless, all weather, accurate and an ergonomic success. It handles so well! And did I mention how easy it is to clean?
I hope we will be able to get Henry single shot rifles over here next year. For the price of a new Encore barrel sans scope, I would get a complete rifle in .243 Winchester, with nice wood and sights, hoping to, someday, bring my heir to a single shot rifle deer hunt. He is still too young, there is time.