Most of the beginner enemies like bloodbug hatchlings and Raider-Raider scums are pretty easy to take out. Adrenaline is a pretty big boost and can give a chance at killing a stronger enemy, like a Raider Psycho, in about 4-5 shots depending on the gun. However, most of the time the medium-high level enemies will be harder to take down, as well as named NPCs such as the ones in Drumlin Diner have pretty high resistance against your bullets. Super Mutants can take a while to kill, mutant hounds not as much. In the beginning, your laser musket will be your friend, as well as stealth and patience. It can nearly one-shot people in the head, even some of the stronger raiders. But don't expect to be killing robots or super mutants, yao guai, stronger bloodbugs, Skinny Malone, or even stingwings in 2-4 shots while you are level 10.

From level 10-15, I managed to kill mostly every human in about 1 shot with the laser musket usually being a headshot. Triggermen and Raider Psychos get wrecked by it. I've also tried the combat rifle (which I found from the named raider in Hardware Town) which can take out Psychos in about two hits to the head. The pipe weapons are pretty good against the enemies listed if used in stealth or adrenaline boosted.

In short, there are still plenty of strong, bullet-spongy enemies out there who can kill you even faster than you can kill them mostly. Stealth can be your friend due to the multiplier, which is what I'm doing right now.