The whole thing gets even more complicated from here. Stihl RM isn't a fast cutting semi chisel compared to some others I used that week. We can close the gap up a bit more with the right chain. The next problem is how fast a full chisel starts dropping that speed advantage. I want to test this more but from previous attempts, a full chisel will lose approximately 5-7% of that speed advantage in 1 tank of fuel. If the aim is to cut as much as possible in half or a full day, I believe you will get more done with a semi chisel. Just for reference, that saw running a 25 inch hard nose bar with carlton 404 semi cuts that same log in about 14.5 seconds and the chain needs a touch up after 4 or 5 tanks.

Hi@@SawChainTheories Thanks for the reply A Qld pro who I recall was called Laurie did years of experimentation and came to his experience/evidence based conclusion that his go to chain was Carlton Semi. He even had a preferred angle of between 30 and 25 deg for the top plate - if memory serves correctly. This fits with you finding Carlton 404 semi gets closer to full chisel speed. Note: I imagine, 404 semi compared to 3/8 full chisel involves a longer rocking cutter, which with other angles kept the same will rock such that it takes a deeper bite, or so I think? only a little deeper but it will enable a powerful chainsaw to put more power through each tooth as it rocks into the wood. Increasing pitch changes the base length that takes part in the efficient rocking motion. I don't know but I expect this is why increasing pitches are matched to increasing power of saws?? Anyway, I went for Carlton semi years ago based on Laurie's experience. I've found it holds its edge well, especially since doing more cutting in clean wood. BUT I don't really know much because I haven't used much other chain. At the rate I use chain/sprockets it'll be some time till I need to replace what I'm using. I expect the sprocket to wear out before my current chains are done. _(1 or 2 passes of the file using my Stihl FG2 is all it usually takes me to get sharp now. If I haven't changed the depth the guide goes exactly into the tooth profile)_ With my next sprocket/chain set I'll be even better at not excessively loading the sprocket and it might last for more of my next set of chains. In the overall process of saw chain comparison with emphasis on time getting things done, (and having fun) I might get 3 loops of semi and 1 of full chisel next, just to get hands on experience of the difference. And in a year or 2 I might get a MS 400. It'll get me close to the 70cc class of a 462 - though just a little lighter and smoother but in most of my cutting, which is smaller diameter stuff, not significantly slower. But a different class compared to my current 55cc, MS 291. I suspect Ray Carlton really knew what he was doing in designing and patenting his Semi Chisel and that's what is behind it's sweet spot of cutting performance and edge retention. I sharpen mine at 35deg top plate and I approach the tooth from 5 deg down. It seems I generally get 3 full tanks before I sometimes start subconsciously pushing to maintain speed of cut, but sometimes I get 4 or 5 tanks in fairly soft but well dried 'Dunns White' gum. I'm getting better at changing chains as soon as efficient cutting under the weight of the saw is lost. I’m teaching myself to let the saw do it all. At the moment I don't have a wood splitter. That's the next piece of kit to most improve productivity for me. That and strengthening the weakness in my left arm, if it wasn't weak I'd be planning for a 462 not a 400, also hand circulation. Anyway, I'm sure you've got better things to do than read my waffling on Cheers d

The file makes it. It's so much easier to get a good sharpening result with the Hexa file that it is worth it. A massive difference between them was quality control. The RM took 28 seconds to make 1 cut when new. The grind on the RS was terrible as well. The only one that cut any good when new was the Hexa.

@@SawChainTheories I get you. I've just heard the pricing for files is through the roof

@@michaelnorth8602 yes they cost about the same has 6 good round files unfortunately. I bought the Hexa in a kit with 2 chains and a file for the same price as 2 RS chains. If the file will last through both chains it's not too bad. Loose it or break it and it's going to be expensive

@@SawChainTheories Im cheap, Im going to wait for a knock off cheap hexa file before using it. I'll stick with my 2% slower round filed chain until then.

​@@nseric1233It really depends on your ability with a round file. I might put up some other videos in the next few weeks but that same RS chain, filed with a 2 in 1 sharpener slows down 5-6%. A Stihl flat file guide slows it down another 3-4% again. If you are good with a file, there's no real benefit but I think most people would do a better job with a hexa file. I'm on the fence with it. I now only have 1 Hexa chain and probably won't buy more.