Is it worth upgrading my laser rifle to a pulse rifle?

I have a laser rifle, which does decent damage and can fire 25 shots for each energy pack. I have the required ingredients to convert it to a pulse rifle, but is it worth it, or will that just eat faster into my ammunition supply? How many shots can a pulse rifle do per energy pack?

And I mean "shots", not "ammunition", because I noticed automatic weapons burn 5 ammunition count for each 3-shot burst.