I've been shot down only three times attacking buffs in a 262 and have killed over 500. That of course doesn't account for many collisions and subsequent augers or getting so close that the 30mm bursts actually killed
me. The 262 is a terror weapon against bombers and barring a lucky shot, the bomber guys are mostly helpless. Outside of flying at 30k, the only thing they can do is hard maneuvering to mess up your shot and/or cause a collision. The rockets seem totally unnecessary but they won't make it much easier.
If bombers are pwning your 262, you are doing something wrong. Drop straight down and watch them fly through the rounds.