Any body know what the ballistic coefficients are for some of the .223 bullets out there....55gr FMJ, 55gr FMJBT, 55gr HP, 62gr FMJ, 62gr SP?  Which bullet is the A-2 sight designed to zero in with at 300m?  thanks, kmclain

If you're shooting battlesight it makes no difference, just don't try to swap ammo types without rezeroing.  

The M16A2 shoots M855 Ball, a nominal 62gr partial steel core projectile.

A 200 meter/50 yard improved battlesight zero works out to 300 meters.

-- Chuck

BC for M193 is .243, and its .308 for M855.

Why type of shooting & at what distances are you planning on shooting at?

For plinking or self defense if you zero with one round you will be very close with the others till at least 100 yards.  At 50 and under you'll get more variance from your shooting position.

90% of my shooting will be at 50-150 yards, but I would like to try my hand at long distance 400-800 yards if I ever get the opportunity. Thanks for the BCs. I'll run the numbers and will probably split the difference on sighting the rifle in.  That way, no matter which I shoot, I shouldn't be too far off.

At 50-150 ranges BCs are of no concern in your case, much as Chuck aluded to, however, in the interest of helping out, all bullet manufacturers are on the internet and all of them have the specs for their bullets, include the BC on-site, (at least all of the ones I shoot):

example: [url]http://www.winchester.com/ammunition/store/cfrlist.aspx?cartlist=MjIzIFJlbWluZ3Rvbg==&uselist=none&brandlist=none&bullettype=none[/url]

Select "View Specs" for any cartridge shown in above link and notice what's up top when page comes up......, your BC.

Mike