Look at Blackholeweaponry.com for a nice stainless barrel. IIRC they have 24, 20, 18, 16" in 2.64 LBC (6.5 grendel). But honestly I wouldn't even bother with anything shorter than 20" if you are going for 1000 yards.
ARPerformance also makes a 264lbc very nicely priced at $200, ish when they have them in stock. My friend has a 20# 223 wylde spr barrel than he loves!
Les Bauer also makes a 263 lbc barrel.
Hope that helps ya.
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