I've had that with stock hook on 3/8 RS chains here in frozen hardwood. Other than that the stihl RS chains do very well in the hardest hardwoods here.
Its not square on the ones I have or have ran. It's somewhat similar to the results you get with the stihl hexa as the top portion of the hook is straight rather than curved. You can achieve a similar grind by laying the head of a grinder way over(can't remember the angle, it's been a bit), and do it in one step, but you have to watch the depth setting closely as the side of the wheel needs to drop below the working corner around. 080-.120"(guessing by eyeballing it). I like it a lot, and if the hexa cuts anything like it it will be a great selling point for those who visit stihl dealers on a normal basis. My favorite benefit of a square chain is not the speed, but rather how smooth it is, the new x-cut chain is nearly as smooth.
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Interesting.
So H-83 vs the round C-83.
I'm gonna mount this one up since I broke the seal on the box. Now, to figure out which saw to put it on. I have a 2252 jred that's set up for 3/8, I haven't run in a while, that sounds like a good fit for what I'm cutting currently
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