Just picked up an acog designed for a 69 grain 223 round. Anyone have any recommendations for a 556 round with similar trajectory? Did a little digging online and haven't come across anything useful.

Thanks

Your primary options are:
- Use 69 grain OTM 223 ammo in the rifle chambered for 5.56. This works really, really well.

- Use 69 grin OTM 5.56 ammo in the rifle chambered for 5.56. This works really, really well. The ballistics will be no different for all practices and purposes, given the limits of the ACOG's bullet drop ballistics lines.

Thanks for the reply. I have a good bit of 556 77gr open tip and thought it might perform similar to 69 gr 223 (heavier/increased pressure). My set up isn't going to be super accurate, and I dont shoot rifles often, but I would like to get it dialed in as close as I can and get familiar with it, in the event I ever have to use it for defense purposes (highly unlikely hopefully). I have alot of 55 gr. 223 and 62, 77 gr 556 to test out. Guess I'll pick up some 69 gr. 556 too. Thanks again.

ACOG's reticles are a ballistic approximation of a given load from a given gun at a given altitude. They cannot be expected to be perfect, and are nowhere nearly as accurate as a higher powered scope where the user has developed ballistic tables for specific loads.

Your own trial and error will determine how well ACOG's BDC works for you. Most likely, you'll find the BDC is adequate for larger targets at reasonable distances.

You will also likely find that relatively minor changes in bullet weight (69 vs 77) and minor changes in muzzle velocity (223 vs 5.56) don't have much effect on the ACOG's BDC for larger targets at reasonable distances. The ACOG is a battle sight, not a precision scope for shooting itsy bitsy groups.

Yep. Not concerned with precision shots. Just wanted something with a little magnification for putting a multitude of shots into an area if need be. My close friend used one on multiple deployements (and now as law enforcement) and attested to how tough they are built. I'm pretty impressed with the build quality and the clarity of the glass. As I don't hunt, or competitively shoot, it should serve me well. I think I'll get out this weekend and see what I can do with the 77 grains I've been shooting. Thanks again for the insight, with my limited knowledge of semi auto rifles and combat type scopes, any knowledge I can pick up from others is much appreciated.