For me anything past 500 yards with a .223 is long range
My goal is too shoot out to 1000 yards and hit my 12x12 steel gong I made.
Stick with 80r and up. SMK's are easy to load for, but there are lots to choose from - most rifles like SMK's tho.
The trick is the powder - Varget or R15
Those will take you pretty far on a calm day!