I have cast, loaded and shot cast bullets in large quantities over the past decades. Engagement into the lands with a cast bullet will give you the best accuracy in most cases. I expand the case necks with a Lyman M-1 die. I leave the flared end of the case as is, if it fits in the chamber as mine do. I don't make much fuss or fanfare over how close or far away the cast bullet is from the lands. Jacketed bullets are another story, though. I usually load my cartridges one at a time, so OAL is not an issue as far as the magazine is concerned.
My current 308 Winchester caliber cast bullet rifle is a CZ 550 Varmint. I use a Lyman 190 grain 311644 and I cram it up into the lands so that the land leaves an eighth of an inch marking on the bullet. I use 18 grains of Blue Dot powder.
Last week, at 200 yards we were shooting at suspended steel disks starting at 12" and going down to 2" and 1.5". My 308 cast load will hit the 1.5" disk 3 out of 4 times at 200 yards. I'm sure that my heart beat and a little wind could have caused the cast bullet to stray from the 1.5" disk. Although, it was probably my shooting.
My buddy, with his Ruger Varminter in 308 with a Saeco #315 bullet (175 grains) and 27.5 grains of Reloader 7, could hit the 2" disk 2 out of 3 shots. The bullet engages the lands severely and helps allign the cartridge with the bore. This is my loading for the #315 bullet. By the way, I got this load recommendation from a Lyman Reloading Handbook and it works great. I chronographed this load at 2045 fps from a 25.6" barrel. The 308 caliber Saeco #315 bullet is tapered and lends itself to lands engagement.
Keep on shooting cast bullets.
Harold Clark