2 of the most underrated rifle cartridges
In my opinion the .223 and the .308 are two of the most underrated rifle cartridges. The reason i say this is because most people have deemed that the .223 max accurate range is 500 yards, and that the .308's max accurate range is between 1000 to 1200 yards depending on who you ask. This isn't the max accurate range for the two cartridges. I personally shoot targets at 1000 yards with a 18 inch barreled .223, and i use a 20 inch barreled .308 at a mile. I could use a 18 inch barreled .308 at a mile, but i prefer the 20 inch for target shooting. I use primarily ar-15 and ar-10 type rifles at those distances, but i will also break out a tac308 for use at those ranges. I also do shoot larger calibers, but that isn't what this thread is about.
Warning: There may be other underrated calibers out there that i didn't mention; most likely because i haven't heard of them or don't have enough experience with them to have a valid opinion.