No one gets in Hollywood's face like R. Lee Ermey. The former drill instructor and 11-year Marine Corps vet has made a nice second career for himself as the go-to actor to fill hard-edged military-man roles, including a much-lauded turn in Full Metal Jacket. For the past three seasons, he's been happily barking answers to viewer questions on Mail Call, the History Channel's combat technology show-and-tell series. "I get to drive tanks," Ermey says of the show that starts its fourth tour of duty on Jan. 11 (10 pm/ET). "I get to blow things up and shoot weapons." Fortunately, the only thing he's shooting today is the breeze with TV Guide.

TV Guide Online: What's the coolest thing you've blown up on Mail Call?
R. Lee Ermey:
Some old ammunition over in Iraq. We worked with the explosive boys, and they had a dummy in a flight suit in the bottom of a pit. Its head was a watermelon. They cut Saddam Hussein's face out of a picture, pasted it on the watermelon and blew it up.

TVGO: Your background was in the military, but have you ever taken any acting classes?
Nope. Never have, never will. I was an instructor in the Marine Corps for years and I'm a firm believer that in order to be a really great instructor, you damn near have to be a stand-up comic. Anybody can act, all they have to do is get over their fright of the camera.

TVGO: What kind of inaccuracies in military films make you groan?
Haircuts. Young actors hate to cut their damn hair because they wanna look cool, and if they don't have any hair, they think they don't look cool. Myself, I buzz it right on down to the bone. I think hair's a waste of time.

TVGO: What films have made the cut, technically speaking?
Saving Private Ryan was fantastic. The Boys in Company C was quite good. Full Metal Jacket was technically perfect.

TVGO: Weren't you the technical advisor on that?
Of course... The authority that a technical advisor has is the power of suggestion. He can't demand to the director that this be corrected because it's incorrect. He's got to be a good salesman as well as a technical advisor.

TVGO: And what about M*A*S*H?
M*A*S*H? Oh, I loved M*A*S*H. M*A*S*H was a thing of beauty.

TVGO: But historically accurate?
You have to understand that they were a medical unit in the rear with the gear and doctors. It's a very, very relaxed atmosphere uniform or military-wise in that situation — they are not military people. You never saw Hawkeye with his shirt buttoned up. You know he was out hitting golf balls with his rolled up sleeves on his uniform.

TVGO: If you're mentally and physically tough but not a morning person, can you make it in the Marines?
Trust me, when that drill instructor approaches the door of your quarters, you will be up, awake, on your feet and dressing before he can turn the knob and get through that door!

TVGO: Yes, sir! Um, you're a pretty intimidating guy. Who was the last person to intimidate you?
My drill instructors back in 1961. [Laughs] And they did a fine job. [Staff Sergeants] Freestone and Sponnenberg were killed in action in Vietnam. Sergeant Devorak retired, and any time I need motivation I can call him up and he'll motivate the hell out of me.