I have an Oregon aftermarket 16 inch bar for a Stihl 170. It runs out of adj room ( stretch)after half a chain so I put another hole in it. It worked and now I have plenty of adj on the screw. I destroyed a good 1/4 bit even after 3 sharpenings, totally useless,de tempered etc... but I managed to re sharpen the other 4 smaller bits it took to start the hole. If I had to do it again I would have used a grinder to break the surface at the new hole location. Its getting started tht sucks. I had to abandon the first hole. But if your wondering about doing this, it can be done ,make sure your center is EXactly where you want it. NO room for error on that. Now I dont have to remove a link after I stretch the chain and that FKKN SUCked.