Breaching is a delicate craft that requires a strong head and a lot of knowledge. Here's a video of an expert breacher doing his thing, make sure you take notes.

Alright boys and girls, it's time to get out your note-taking gear. Go on, get it out of your little cargo pocket there, I know you're still carrying it around with you everywhere you go. If you don't have it, it's okay, your Sergeant will pay later.

Alright, step one for breaching a door properly. Find the largest E2 in your platoon. Step two, ensure that E2's helmet is securely fastened to their head, and that their chin strap is on properly. Step three, throw that E2 through the door with no less than two of the E3s from your platoon.

That is how you properly make entry into a room.