It's designed and chambered for. 223 Remington. Some of the militarised models may have a 5.56x45 chamber more ideal for 5.56 ammo than the "standard" models (like the Mini 14 Ranch). There were also models chambered in .222 Remington, for export to countries which prohibited civilian ownership of firearms chambered in military calibres, though these are a bit rare.
The Ruger Web site says the Mini-14 Ranch Rifle and the Mini-14 Tactical Rifle, can be used with either the .223 or 5.56mm round: Mini-14 Target Rifles ONLY accept .223 Rem. ammunition. 5.56 NATO cannot be used in this model. Probably due to tighter chambering dimensions for accuracy.
yes, although feeding difficulties with 5.56 ammunition aren't uncommon with the Mini 14 Ranch.
This rifle was designed to handle 55gr.bullets of lighter.I do not believe that the heavier 62gr will stabilize with the rate of twist of the mini-14.
@ 4kilos
Chamber pressure is determined by the cartridge, not the rifle.
Semi automatic rifle made by Ruger.
580 is the newer version of the Mini 14 Ranch, minor engineering changes, improved accuracy, etc.
Good
It was never fired. There was a standoff between the protagonist's uncle and the local cop, where the protagonist had a Mini 14.
50 USD or so
10 rounds
You rifle appears to have been manufactured in 1983.