Miserable. The FMJ bullets are the most inaccurate bullets there are. How your rifle shoots them depends on your rifle, but they will be the worst bullet your rifle shoots. There are always some exceptions but FMJ are the cheapest bullet and have the worst quality control of all.
Jack is right! I have seen them shoot one inch 5-shot groups at 100 yds. but that is certainly not the norm. If they will do 1.5 you have found a good load and this may be on the more realistic side of things to shoot for.