I doubt that the WLN in that light a weight would be nearly as accurate in most guns. The WFN is my recommendation in such a light weight, and will be very accurate, but may give feeding problems in many auto, but less so than the WLN which would have the capability of being seated out farther before hitting the rifling.
So, as far as killing punch, there is not enough difference that one could tell it, but for feeding reliability and velocity potential, the LFN gets the nod.
I want to make something patently clear here. --- With all this discussion on the ACP, and my statement that it is an adaquate big bear defense gun, I AM NOT RECOMMENDING IT! Use it if you want, and have no better option, but the optimim would be a 44 mag or 45 LC loaded to give a DV of 125 or a bit over with bullet weight of 300 gr, with 280 gr being just fine. (A 41 mag with full loads and 240 or 250 gr WLN will do about as well, except against large bone joints.) If fast repeat shots are wanted, and light weight, use a S&W, which isn't so plesant to shoot with heavy loads, but it's double action is far more reliable for fast repeat shots than an auto, in my hands for sure, and I believe in most peoples hands. If an auto jambs or misfires, one has to be very familiar with it to clear it quickly. With the double action revolver one just keeps clicking til it quits banging. With the above type loads, judging from field reports, one will have to be a very good and fast shooter to put more than two rounds into a bear before it is down for the count.