Mr Bisley,
I also have a reduced load running the same bullets and TrailBoss. These are for those days where you forgot your shooting gloves or you just wanna "Plink" with the 1/2 incher.
Same 475gr HC Bullet but over the top of 10gr of TrailBoss. These will clock around 790fps.
BTW, I run Large Pistol Magnum primers in my handloads as well.
Good Shooting to you