Sometimes there is a weird curb with reloading, try working the load from min to max and look for the sweet spot, you may find the hot load brings accuracy back in to play, could have something to do with the ammo as well and how it was reloaded, noticed you using cast. I don't shoot cast, just jacketed ammo, where I hunt Jacketed ammo works well, if I were to hunt Browns or cape buffalo etc...very large animals, I would use hardcast for deep penetration on a large animal is needed, but for where I am hunting Jacketed ammo does the trick on White tail deer/Black bears up here in NH. Aim small hit small. RAMbo.
P.S. note: I noticed keith's 405 bullet is Jacketed and the one your using is cast, this may be your problem.
P.S. note: I noticed keith's 405 bullet is Jacketed and the one your using is cast, this may be your problem.
