The problem with HO attack on bomber is that you will find it hard to set up another pass. After the HO you are flying in opposite directions and you cannot turn before you clear his guns range. Then you blow some speed on the turn and have to chase it. HO attack is good if you don't have too much E and wish to get just one kill.
A much better systematic method is to fly parallel, above and slightly to one side. The only effective way he can track you is from the top gunner and the lead he needs to make is really confusing. To aim ahead of you, while looking up and back he may need to elevate more than 90 degrees - which he can't. This requires turning to the front and elevating. The 'little to the side' part add another degree of freedom and looking straight up, having to rotate seeing nothing but skies, he can loose orientation easily.
From your POV, from the top, the bomber exposes the largest area - especially of wings and engines that you want to hit. If you have tracers on, take an early shot, watch the tracers and correct. This is actually an easy shot to make - to me, easier than dead 6 and I am a sub-5% shooter even after 6 years playing.
Follow through with the attack and level just under the bombers altitude. If you started from 'little to the side', you will have a few degrees off of his flight course (if not - correct yourself) and let the speed carry you away. This is again confusing for him. He needs to switch to another gun position, orientate himself, turn the guns (they will be off due to tracking you from the top position) - by which time you will be 800+ yards away. Don't climb till you are out of danger, ahead of him and in slightly diverging course.
Then start pulling up to zoom, then sustained climb - don't turn back, let him overtake you and you climb above, parallel and a little to the side. You are back where you started, ready for another attack.