A rifle may do a lot of damage vs. your average 12 HP hero. The AK-47 for instance does 5d6+1 points of damage, and thus a hit from such a weapon is absolutely devastating, and shouldn't it be? And its not like the average 18.5 damage will pound you directly into the negatives no matter where you are hit; Arms and legs has 1/2 your HP, and your 12 HP hero who is hit in the leg by an AK-47 will loose the function of the leg, be reduced to 6 HP, start bleeding (requires first aid in order not to bleed out), and needs to make some HT rolls to avoid permanent injuries. Head shots, while difficult to score, deals 3x damage to your total HP, and is almost always immediately lethal, unless you roll all ones, and even then you are in trouble.
So yeah, as the AK-47, when fired by your average druglord henchman, afghani mudjahadin, of central african child soldier, will spit out 3 bullets/round if he is using semi-auto (wich means that he could be aiming his shots and actually hit - Watch out!), or 8 bullets/round if he just sprays bullets in your general direction, a TPK can be achieved in a second by even the lowliest 0-point mook, and don't even think about confronting a platoon of dug-in infantry with rifles, MGs and RPGs unless you have a tank... Or rather several.
But I don't think that the lethality of the system makes the characters feel any less heroic. On the contrary, it gives the players a feeling of real danger to their characters, and suddenly fighting even the most humble foe gives the players a feeling of actually risking themselves for the cause. Some players don't like it, but others do.. Its hit or miss really. Ive been playing a combat heavy GURPS campaign with some fellow army guys some time ago, and it worked great, but when I introduced the system to my D&D friends, I killed them all in the first encounter, and they never wanted to play the game again. The phrase "Hes only carrying a .38? Bah! I have plenty of hit points. I charge!" has since entered our hall of famous last words.
