Bore cutting (also known as plunge cutting) is one of the best and safest practices in tree felling, and it is the method that we here at the Timberland Investor promote as being the best for back cuts. That said, bore cutting often gets a bad rap (from the misinformed) because it requires using the kickback zone to cut into the tree. Properly executed, however, the kickback zone is not used until the saw is sufficiently buried into the log. This creates a sort of containment chamber that allows you to bore cut with the tip of the saw without causing any kickback at all. It may sound intimidating at first, but with a little practice, you will find it isn’t difficult at all and in fact yields many benefits to the feller, including massively improved safety when felling rotten and defected trees. In this article, we will discuss everything you need to know to safely and competently bore cut.
Step 1: Begin Cutting Into the Tree With the Attack (Bottom Tip) of the Saw
With your notch having already been cut, begin your bore cut by positioning your saw parallel to the ground and taking the attack of the saw (the bottom tip of the bar, opposite of the kickback zone), and using it to cut into the tree. The initial cut is best placed positioned back a bit from the hinge, as this provides a margin of safety that prevents you from accidentally cutting into or through the hinge. It is also good practice to take your time to ensure your bar is truly level before initiating your cut. The two most common bore cutting mistakes of beginners is creating uneven and slanted cuts on either the horizontal or vertical axis of the tree.
Continue this cut until the bar is dug into the stem by at least half of the bar’s diameter.
Step 2: Rotate the Saw to Be Parallel With the Hinge
Once the bar is dug into the stem at least half the diameter of the bar, it is time to rotate the saw to be parallel with the hinge. At this point, the kickback zone will be engaged, but the trench dug in step one of the bore cut will contain the bar, preventing it from causing kickback and jumping away. You may feel the saw at first bounce around a bit inside the cut, but it will be fully contained. However, it is important that you move onto step 3 quickly and not hold the saw in this position for long, otherwise the cut will widen, potentially causing the bar to escape.
Once more, I will reiterate that the two most common mistakes beginners make are creating uneven cuts on either the vertical or horizontal access, so be sure the bar is relatively parallel with the hinge and notch before proceeding. This is why the bore cut was initiated with offset toward the rear. It gives you an error allowance of about 15 degrees.
Step 3: Push the Saw Straight Through the Stem
With your saw angled and aimed properly, begin the bore/plunge by pushing your saw straight through the stem. Keep going at full throttle until saw dust spits out the opposite side. stopping or feathering the saw risks the chain getting pinched, so you have to commit! If your bar does not make it all the way through the tree, you will have to line up your cut and continue from the opposite side of the stem. In these situations, it is best to start from the back on the opposite side and work forward once the initial cut is made.
Step 4: Move the Bar Forward to Set the Hinge and Then Back to Set the Strap
Once the bar is completely through the tree, we can cut away the margin of safety we established earlier and cut the hinge to its proper width (usually about 10% the diameter of the tree). Push the bar toward the hinge to do so, taking your time to do it carefully, checking both sides frequently to ensure an even cut.
When you are satisfied with the thickness and quality of your hinge, pull the bar back and finish the back cut. Leave a section of uncut, sound wood toward the back so you can finish the cut from the outside. This part is called the “strap.”
Step 5: Cut the Strap
The final step of bore cutting properly is cutting the strap to fell the tree. First. Lightly set a wedge in the back cut. This just acts as a place holder to prevent the tree from closing in on the back cut once it is released. Once the wedge is set, cut the strap from the outside, and be prepared to move away quickly. If the tree does not fall immediately, further wedging or levering may be required.
That’s All There Is to It
Despite its reputation, executing a proper bore cut without causing kickback is not difficult. The key is the initiation of the cut shown in steps 1 and 2. It takes a bit of practice, but one you get used to it, you will find it is really quite simple. If you are still feeling a bit nervous about giving it a shot, try it out first on a heavy log or high stump. That allows you to get the hang of the mechanics of the cut before you try it in a higher-risk setting. In any case, no matter your skill level or situation, always be sure to exercise usual felling and chainsaw use precautions. Use common sense and be careful!