I use w231 and titegroup in my 303 british for 1000's of rounds. Speaking w231,ive used as low as 3.6gr behind 96-305 gr cast bullets and ive used up to 10gr behind the 220gr ( and down to 96gr and about 8 different weights inbetween)( 240, 260, 305gr bulletd all keyholed and at low enough velocity i could hear them cork screwing
I was also working towards 1050fps. I nebrr had any signs if pressure at all. All primers always look like like there were fired from an empty case. Also brass lasts over 100 relaods and never needs to be trimed.
Works well, i use it at about 10-25m
If photobucket did steal all my pics id have lots to show for my testing.
Also the vast majority of the bullets are pure lead, no lube sized 0.003" bigger then bore.
I have also used a load of " hard cast" that i purchased to test againt some of my designs, i used the same load data for pure lead as " hard cast"
Ed harris has loads of excellent data and info on reduced cast loads using pistol powders and shotgun powders