How to place a cam
Cams are one of the easiest types of pro to place. Many times however, they can be placed better with more “purchase” giving a more secure placement for stronger fall protection. A cam is a pretty simple active type of protection for climbing. You squeeze the trigger, the heads contract, you pop it in , and the heads retract, “caming” into a good horizontal or crack. With a little practice you can stuff in cams quickly and easily making a lead fast and conserving valuable energy needed for difficult moves ahead.
It is recommended to go out with an experienced lead climber or guide and practice several dozen placements in cracks and horizontals to become comfortable placing cams. It is also an excellent idea to find a climb where you can place a cam near a bomber cam someone knowledgable has placed and take a fall on some of your placements so you can build a trust in your gear before leading an entire climb on gear you placed. Trust in your placements is important and without it you may as well be free-soloing the climb. If you don’t trust your gear, you shouldn’t be placing it.
The Beta
Find a crack and eye up the size you think you will need. A good trick to get the size you need right is to squeeze your fist and make fist shape near the cam size or claw your hand or stack fingers. Compare this and practice comparing these hand shapes with your cam sizes. Then you can do this on a climb and know exactly what size you need.
Look for solid rock without any fractures or flaking texture that may not be secure. Flared cracks are not great, an hourglassed shape (wider at the top than bottom) is best.
Squeeze the trigger and place the cam. Release it and make sure the heads are not overcammed or undercammed. A 45 degree angle is the best purchase.
Make sure the cam is not stuffed to far into the crack or it may be very difficult to remove . Many new climbers panic and stuff the cam far into the crack. If you do this you may not get it back. Good placements can be near the mouth of the crack.
Test the cam by applying a slight downward force. Don’t jerk or yank at it just a slight downward force to test the grip and purchase.