Having Trouble getting to the Boomers with the artillery coming down on top of you, tried the B line thing but was no help with me since I cant get it right.

if your on hard core i cant help yea but on regular put it on very easy run and spam stimpaks

Yeah, afraid I am on hardcoe mode; ;

When you enter the area on the left there is a burned out house. run into it and go to the wall closest to the direction you are going. Stand there a minute and let them bomb like crazy.
You will notice the bombs fall in pretty much the same place. I believe the next safe place is by the cliff ahead of you. When they stop run, when you get to the cliff wait for the bombs to come and go again then run in to the gate.

If you stand back at the start you can see where the bombs fall.

Thanks ill try that.