Centerfire ammo is ammo which fires when it is struck in the center by a firing pin (all modern ammo except .22's) as opposed to rimfire ammo which fires when it is struck on the rim by the firing pin (no modern ammo except .22's). Your Mini-14 is centerfire.
Your Mini-14 is centerfire.
Every gun in my house is centerfire except for my son's plinker .22 rifle. Gosh, I suppose my shotguns are also, and I wasn't even counting them.
.17HMR is pretty "modern" ammo. It is rimfire. It has only been out for about 18 months.