Where can I buy a nozzle for a beckett oil burner? Does home depot or Lowe's carry parts?

I do not believe they carry nozzels... usually you have to get them through a distributer or supply house, and they usually want you to be a contractor to sell to you.
Do you know what nozzle you need? And where do you live? Might be able to find somewhere for you.

Size 75, angle 80, spray A. I live in NH

Try finding a supply house in your area and call them. You might also be able to oder a nozzle online. Unfortunately nh is way away from me and anyone I know.

Oil Furnace Nozzles (http://www.heatingandcoolingwarehouse.com/Oil_Furnace_Nozzles_s/61.htm)

Try here too. Looks like they could ship you one.

That works! Thank you for your help