Depends how close you want to be. I use 55gr and 69gr, neither of which match the JM1 reticle's calibration, with the scope zero'd with 69gr at 200y. (Depending on stage setup, 55gr out to 200 generally, 69gr for everything beyond)That has been close enough to hit targets out to 500y without problem on the clock. Without citing specific examples off Strelok right now, the hashes are generally no more than 25 yards off for the 69gr, depending on outside temperature. As it gets colder (such as 20+ degF colder from the zero weather), the hashes can be up to 50 yards off at the 500y hash mark if memory serves. In that case, you just hold top of plate instead of dead-on......
+1.
Never used 55FMJ to test the reticle calibration. My three loads are 50 vmax, 55NBT and 69 SMK. All are within .3 MOA out to 400. Close enuf for the work we do in 3 gun.