most .223 rifles have a twist rate that is too fast for cast bullets. shooting them in an AR is a bad idea as they'll likely disintegrate in flight. even light jacketed bullets have this problem. cast is ok in rifles with a 1:12-1:14 twist (bolt actions) when velocities are kept below 2600 fps or so.
as for the glocks, the information i've seen is there was a kaboom several years ago and glock blamed it on the cast bullets. i know many people who shoot cast bullets in polygonal barrels and never have a problem but i would suggest buying an aftermarket glock barrel with cut rifling just to be on the safe side.
"Glocks may well work everytime, but they have all the beauty and character of a black rubber doorstop." - Rice Paddy Daddy