Green chain doesn't bore well. Whatever bar/chain combination you use, it must be well tuned to the tree species, the saw, and your cutting style.
There are other options for cutting a leaner than boring, such as the coos bay/triangle cut. A sharp chain, and a quick cutting saw are part of a good falling plan when dealing with leaners. On leaners most times I make very shallow face cuts, but not too shallow the tree sits down on the bar when I bore it lol.
You should familiarize yourself with bore cutting on a tree that's already down, then practice on a stump of a tree that's already been dropped. When just starting out with bore cuts I recommend making them with the top side of the bar away from the hinge as the top side will walk in and you can easily cut your hinge, consideration should be taken in a like manner for your trigger. Once you have made the bore cut and set the hinge thickness, then you can cut towards the back leaving a trigger(dont go too far) if you're already on the high side, if not move to the high side before cutting towards the back to leave the trigger. I typically leave a trigger and remove the saw and then I cut just below the back cut to release (some will argue with that, I'll just say, when their saws flying thru the air, I hope there's a video

). If I'm cutting out the back it's because the tree doesn't have a heavy lean, and most times in that case I just make a standard back cut.
Best thing is to get someone to help you fall it that can guide you, even if you make the cuts.
Hope this helps.