I am with Kessler Farms. There have been improvements in anti-kickback chain, but it still doesn't cut as well as plain chain.
We may have a terminology problem. The actual cutter is typically one of three shapes: chisel, semi-chisel, or round (also called
chipper). A chisel cutter has a right angle between the top plate and side plate, so that when it is sharpened there is a sharp point at the intersection. SkyPup's attachment shows a chisel cutter. A semi-chisel cutter has a mitered or slightly rounded corner between the top plate and the side plate. Instead of the sharp point of SkyPup's chain, the corner is flatter (blunter). The corner between the top plate and side plate of round chain (
chipper chain) is truly a quarter circle.
Chisel chain cuts best because the sharp point at the corner pierces the wood more easily than the mitered corner of semi-chisel or the round corner of
chipper chain. However, the sharp point also dulls much quicker, particularly if the wood is dirty, or if you let the moving chain touch the ground (to say nothing of a rock).
Chipper chain requires more power to cut than either chisel chain or semi-chisel chain, but it also stays sharp longest because the rounded corner has no "points".
Chipper chain is most often seen on the "Beaver Blades" used on brush cutters since it spends much of its life cutting dirty wood close to the ground or in the ground itself.
In addition to the shape of the cutters (chisel, semi-chisel,
chipper), the shape of the ground cutting edge can also vary. All three cutter shapes can be sharpened with a round file or stone. SkyPup's chain was sharpened with a round file/stone and you can see the circular profile on the cutting edge of the side plate. Semi-chisel and
chipper cutters can only be sharpened with a round tool. Chisel cutters can be sharpened with a round tool or a flat file. Chisel cutters sharpened with a round file or stone are usually referred to as round chisel (meaning chisel cutters, with a square corner, sharpened with a round file). Chisel cutters sharpened with a flat file (actually an angled file) are called flat chisel cutters. Flat chisel cutters have the sharpest point of all, and cut fastest of all cutters, but the sharp point dulls so quickly that flat chisel chain is not commonly used in the woods. It is also very difficult to sharpen a chisel cutter flat with a file, and electric sharpeners for flat chisel chain are very expensive.
Chain can be anti-kickback whether its cutters are chisel, semi-chisel, or
chipper. Chain is made anti-kickback by either raising the side links to shadow the raker and cutter edges so they will not hang on vines or the tree if the top of the cutter nose touches, or by putting a projection on the bumper link that shadows the raker and cutter. Anti-kickback is most handicapped when boring into a tree with the nose of the bar, since the heightened side links keep the cutter from digging into the tree as it goes around the nose. Anti-kickback is also handicapped in deep cuts because the heightened side links fill the slot that the chips normally occupy as they are being pulled through the cut.
Oregon has recently introduced an anti-kickback chain that relies soley on the shape of the rakers to reduce kickback. If it works it will virtually eliminate the disadvantages of normal anti-kickback chain.
Gordon 21 is right about keeping the rakers at the proper length. But be sure to use a guide rather than just guessing. Most rakers are set at 0.025-0.300" below the top of the cutting edge on the top plate, and as little as 0.005 error can greatly effect how will the chain cuts and how smoothly it runs.
I attached a copy of SkyPup's picture of round chisel chain with a few notes relating to the above.
PS: I understand the dangers in bore cuts, but they are sometimes safer that regular cuts, for example to avoid barber-chairing on large trees with substantial lean. And they are the only way to cut a tree whose diameter exceeds the bar length.
