It has been troubling me for some time how ineffective VATS shotgun criticals were. When making a workaround that replaced the extra damage of shotgun crits with a knockdown effect (to make real-time and VATS criticals equal in effectiveness), I accidently found out critical actor effects are correctly applied to each projectile in VATS as well as real-time.

I have thus made this mod, which replaces the shotguns' criticals with damaging actor effects, effectively fixing shotgun crits to cause the same damage in and out of VATS!

http://www.newvegasnexus.com/downloads/file.php?id=36420

Please let me know if this works for you!