My brother runs 140 TTSX at 3250 with 63.5 grains of RE17 (Tikka T3)... which is quite similar to 4350.
You could also back that RE22 load off a grain and give it a run... IME, it's hot loads that tend to get real hot when the mercury perks. A grain or grain and a half reduction could lead to little lost on the top end, with a lot more stability when it gets hot.
I've also seen good loads go bad, when it's hot out and you let one stew a little in the pipe.
