What chamber would you pick if you had a free barrel: .223 Wylde, .264 LBC, or 6.5 Creedmoor?

I have big and small frame guns so it's just a matter of building an upper. My current .223 Wylde is a 16" set up for 3-Gun and my .308 Win is a 20" gun for PRS Gas Gun. I shoot 6.5 Creedmoor in a bolt gun so I'm looking at it over .260 for the ease of buying one type of case. The only reason I am looking at the 264 LBC is because I really don't like the big gassers and I have an unopened 500ct box of Sierra 123gn Match King on the shelf.

I will use this for the PRS and 3Gun Nation LR matches which only go out to 800yds. The last match I finished 5th with the 308, the team in first shot 223, and all the top five were TAC so I'm not sure I need the Creedmoor and the Grendel doesn't offer a huge advantage over 223 and won't beat my .308 load.