43.5gr H4350 in my 243/6SLR under a 105 hybrid was good for 3200fps in a 26" Hawk Hill 4 groove. Ran it that way for ~200 rounds, but backed it off to 42.5gr for ~3130-3140fps.
At ~750 rounds, it'd slowed to 3080fps. Now, with 994 on it, it goes 3060. Still shoots great.
I shot in 95° temps at...