Like others advised....using TiteGroup the published minimum is 4.1 grains at 1069 fps....and max is 4.4 grains at 1136 fps....
I'd suggest you not be a "chemist" and ever go below the published Minimum or Maximum...on any powder / but especially not a powder like TiteGroup that is a relatively hot powder.
Berry's are not Jacketed bullets...they're plated bullets....although they tell you to use mid-range jacketed load data ...they also tell you not to exceed 1250 fps....on their website....so I'd suggest you visit there as well.
http://www.berrysmfg.com/default.aspx?n=562957
Overall length on FP bullets can always be a feeding issue / and seating any bullet too deep in the case can significantly increase pressures.../ I'd certainly keep your loads at the published minimum of 4.1 grains until you work out the feeding issues on these bullets.