I had to change the firing animation to the plasma pistol so there would be proper animations while aiming downsight. As such, the beam will now "jump" off the target. Don't worry, you'll still hit to the best of your skill level/weapon condition.
I have yet to find a laser rifle to see if it has working ironsights. If not... then I'll mod it too.
http://www.newvegasnexus.com/downloads/images/34847-1-1287679906.jpg
http://www.newvegasnexus.com/downloads/images/34847-2-1287679906.jpg
http://www.newvegasnexus.com/downloads/images/34847-3-1287679907.jpg
http://www.newvegasnexus.com/downloads/images/34847-4-1287679907.jpg
http://www.newvegasnexus.com/downloads/file.php?id=34847