This technique is simple and, as its name suggests, is quick. When some speed is necessary, but caution is still mandated, this technique will work well. A quick peek allows you the ability to get an instant's worth of intel before entering a room. Sometimes more than one look is necessary; in that case the second peek must be different than the first. If your bad guy is in that room looking at the doorway, he will see your first peek and be counting on you to stick your head around that corner at the same place as your first peek. Ensure that the second peek is higher or lower than the first. Then, after you have made that quick peek, get into to that area quickly, as things can change in an instant. Even a few seconds can make a difference in what you saw during your peek, and what you see when you make your entry.
If you can use a colleague as a cover man while you are doing your quick peek, perform it with your weapon holstered and both hands braced on the wall. This will give you the ability to do this technique even more quickly. Bracing yourself gives you speed; you can perform several peeks in mere seconds. Remember to draw that weapon again before making the entry.
Slicing The Pie
This technique is performed by using the cover of a doorway or corner and simply moving incrementally so that you can get a small "slice" of the room. The only thing visible to any bad guy in that area should be your weapon and shooting eye. If you do spot a danger area or a subject, you can quickly move back right or left to be fully covered. I like slicing the pie since it requires nothing more than my weapon to be out, and I am in a stable shooting platform ready to engage. To make this technique even more effective, bend slightly at the waist to ensure that your lower body has as much cover as possible. In a doorway, partners can perform this technique simultaneously from either side.
I like to use this technique after utilizing one of the above methods. The limited penetration involves bringing your shooting arm into the room while only exposing your shooting eye(s). A limited "pen" allows you to cover a subject, or "hold" a room before entry is made, or while colleagues clear a hallway or stairway. If you use this technique before any other visual clear, you expose your weapon to any bad guy in the room that may be close enough to grab it.
The ultimate entry tool, the shield affords maximum protection while on the move. Used in conjunction with safe tactics such as lipping, splitting, and slicing the pie, the shield is a life-saver. Much more versatile now that they come in a fold up configuration that allows for easy storage, shields are quickly deployed and make room entries more tactically sound.
Making an entry into a room or house is fraught with danger, ergo the term "Fatal Funnel." Pausing in a doorway gives the bad guys the perfect target with which to take us out. Utilizing a slow, methodical entry, combined with visual clearing techniques, will keep you tactically sound and above ground. Be safe brothers and sisters!