I never ran 296 and 300MP through a chrono with a 4" barrel that I remember, mostly 5" and 6 1/2" barrels and through a rifle. And I had some less than stellar experiences with 300MP when I first tried it with my old 5" 27-2; ran dirty as heck and didn't seem overly energetic either, but I didn't have a chrono then and that old 27 was needing a tuneup bad with some endshake and a good bit of throat erosion. I might have to give it another chance in revolvers. It ran real well in 44 Mag out of my Desert Eagle.

On your 296 loads, are you using a very heavy crimp? I've found that helps with 296 too.

Thanks for posting up your results. I don't shoot much in 125 grain any more; I shoot 140 and higher. But you've given me some data to look at here that makes me reassess using 300MP.