Tge 62 gr bullet was shot with my ar.
Yeah, that is going to be rough at 1000 yards. Shooting at any distance, staying supersonic to the target is important because the bullet trajectory destabilizes a lot going from supersonic to subsonic.
This is why lower velocity accuracy loads that do great at 600 might do much less well at 1000, especially in cartridges such as 223 and 308.
A great site to use to predict whether your loads will work at all at 1000 yards (or any other distance) is http://www.jbmballistics.com/ballistics/calculators/calculators.shtml
Use the trajectory calculator, find the bullet you are using in the top dropdown, specify the muzzle velocity, enter the temperature and humidity (can make quite a difference) and any other relevant information.
Click Calculate and look in the 'mach' column for 1000 yards. If greater than 1, the load might do OK at 1000. If it is less than 1 it will most likely do very poorly. Ideally you will want to be mach 1.2 or higher at 1000 and you will see it is not necessarily easy with a 308 and very difficult with a 223.
The calculator will give a lot of other very good information too, such as how to dial your scope from one distance to another, both elevation and windage.