Being both of these weapons are pretty similar in general performance it's a hard sell for me to choose which I want as a main combat side arm. When I mean main combat, I mean something with a good supply of affordable ammunition but gives up a good return in performance. Plasma is expensive for example, and fully auto weapons just guzzle ammunition too fast for my taste.
I go with long barrels, full stocks, and max damage upgrades possible for both of these weapons per shot with Red Dot sights for easier close range aiming. Being I don't use "Full" scopes I don't use the stocks/barrels that help support sniper scopes either which improves hip fire accuracy as well. But try to use ones that improve "Aim" accuracy.
Combat Rifle win with Max Damage and VATs Accuracy advantage. (but has to use .308 upgrade to beat Laser Rifle in Damage)
Laser Rifle wins with rate of fire, Better Aim and Hip Fire Accuracy.
Both seem to have the same range pretty much. Laser Rifle seems more affordable to use... but man the VATs capability of the Combat Rifle is very good, I defended the USS Constitution using VATs from it's Deck down at people below and had a 80%+ torso success rate on most enemies.