If going the factory load route I would use a 50gr. Hornady and use the brass with a close approximation of the same.

I've never had a 722 but have loaded for 3 700's in 222. The Hornady 50 gr. V-Max with RL-7, R-10x or H/I 4198 work very well. Never used LT-32 yet with 50's but that's another great 222 powder.