i have purchased some 44 cal. cast performance LBT 255gr. for my 44mag. anyone have any info on these type of bullets

Is your 44 mag a rifle "Ruger M44" or a pistol like the Super Blackhawk?

I load for both and could offer you data for either. I cast my own using the Lyman "429421" Elmer Keith bullet which is considered a 240 gr. bullet but my alloy drops it a 255 grains.

sorry it is a S&W 629 4" bbl

I have seen discussions of this bullet on rugerforums.com, but have not shot them in my 629. I have shot them through my BH 45 and the leading was not too bad unless they were loaded either too mildly or too hot.