Do you use a progressive gauge Steve? OR do you use a multi tooth contact gauge ( straddle/ saddle type gauge? Basically, do you tend to keep the teeth even? Anyway, as I said you are not duplicating 'text book filing' as you say It works with that set up in the oak on a stock chain. The 261 I use sometimes, already had a hand filed semi chisel chain on it that seemed fine to bore ash with at first but I couldn't do much with it in terms of self feedings at 0.025" other than the buck but I would still lay on the dog every chance I could. Needless to say, it would be all wrong trying to make a Humboldt when the little dog doesn't reach (Due to the buttressed or otherwise) or when bumping collars. Of course I am going to go back to my roots of life, my bread & and butter when put into a corner with some added 'hook & drop' After all, "we're here to log not f_ck the dog" (is the mentality). Well now it doesn't bore properly with some hardwoods.
Then you no what I did next, right?
Your welcome.
, would be real bad for boring into hard seasoned ash or locust, and lets not talk about frozen sugar maple 
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