The Mini originates from the AC556 (select fire) - which was to compete with the M16 when it was having development problems. It never 'happened' but it was Rugers plan. Anyone that says the Mini-14 was first is wrong.. same with the Ranch rifle. The SN 180 seriese Mini-14s are really an AC556 receiver that is not fully machined. Starting with the 181 seriese the receiver is actually narrower and shorter... this new receiver was used until the 580 seriese. The 'Ranch' rifle was merely a gimic to validate the mini as a Ranch gun or a scope-able rifle....
Ruger hoped the AC566 would be destined for the die-hard M14/M1A military units. It never materialized. But the public loved the design.... evidenced by the millions that have sold under the title Mini-14 or Ranch Rifle.
It is an affordable & practical Semi-Auto 5.56 rifle.
To credit the design, Ruger at one point had redone the Mini in 7.62x51/308 called the XR1 or something like that. There was and still is a devoted following to that type/style of action. Hence all the M1As that are circulating.
Remember - Non-Restricted and will never jam....