Are you chambered for .223? Still maybe the best all-around cartridge for the AR, but I built my M4 thinking to go suppressed subsonics at some point, so I chose the Blackout, which also gives me a large range of bullet weights from 95 grain to 220 grain, although I mostly stay with 125 and 155 grain. The 155's are great out to 200 yards, use Sierra MK's. Past 200, the drop starts becoming significant, but I can still hit steel at 300 with them. The Grendel I've had out to 1125 yards, just as they are going trans sonic, with 123 grain Lapua Scenar boat tails. It's surprisingly accurate at 1100 yards, 1-1/2MOA.
Our club range only goes to 300 yards, so most of my shooting with the Grendel is at that distance, but now and then I make a trip to a couple of 1000 + yard ranges a few hours drive away. I shoot with a few guys that have some nice .308's and I can stay with them as far as mine will stay supersonic.