Only if it is marked ".223 Remington" on the barrel.
.223 Remington ammunition can be fired safely in a 5.56x45 rifle; 5.56x45 ammunition cannot be safely fired in a .223 rifle. In the case of some partially imported rifles, they are marked .223 Remington in spite of having 5.56 chambers. This is done for compliance with BATFE laws regarding importation of certain firearms types. If in doubt about the compatibility, call the manufacturer - they're the ones who would know best.
The 223 is considered a Short Action rifle.
Possible, but, costly
No, this is a dedicated .223 Remington chamber, and that's the only ammunition which should be used with this rifle. While the two rounds are matching in dimensions, they are not identical.
yes. the 5.56 is the 223 caliber ammo.
100-1000 USD
$700
Them twist rate of a Winchester model 70 rifle in .223 Rem.is 1"in 9".
No. They have matching dimensions, but differ in other areas, such as neck angles. .223 ammunition can be safely fired in a 5.56x45mm chamber; 5.56x45 ammunition is not recommended to be used in a .223 Remington chamber.
The equivalent of 5.65 mm ammunition is .22 caliber ammunition.
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.
Only the factory knows and they are not telling.