You can shoot the 7/8 ounce loads if it makes you feel good. They do hold together great, but don't fool yourself into thinking they are the best choice to break targets. You would be further ahead when it comes to breaking targets, to shoot 1 or 1/1'8 at reduced speed. They hold together great also.
You won't save that .70 cents a box, but you will probably break more targets.
