I see Bucking Horse has a (new to me) 223-62 grain:

https://buckinghorseoutpost.co...-on-orders-over-175/

Anyone use/know of them?

They are small ammunition company based out of Ky that started making had precision projectiles for bench rest shooters and now have grown into the live ammunition business.Personally I’ve shot the 223 52 grain it shoots great and their 243. Check out their website they have free shipping on ur first order. Ammermanbullets.com