Spit out milk

Maybe you’re feeding him a little too much? Babies will go on and on because they don’t know. Can give small amount frequently instead of big amounts. Mine projectile vomit every few days it was quite worrisome until I reduced her intake and gave at frequent intervals instead. If all else fails maybe it could be the milk. Can try changing milk if he is not pooping or having wet diapers every 2-3hrs.