Depending on the version, it will not take much to knock these fighters out of the sky (ki-43), the later versions will survive a bit better with self sealing tanks and the armor behind the cockpit, all in all the structure or each aircraft may as well be night and day. Every indication says the brewster will be able to handle much more punishment then the ki-34 ever could. It should also be noted the engines caught fire very easy. Making even head on's while in the ki-43, a very bad idea.
I also retract my statement about the HE ammo used, not only was the round not as good as the .50 right off the bat "less power and less m/s",the rounds tended to blow up on impact before any type of penetration was made, in most ranges they wouldn't even have a effect on normal a/c plane skin that a copper jacket .50 cal would have. That kind of make me sad in ways,but i still wonder what the effect would be if it hit a plane with a damaged fuel tank, if it would set fire better then normal gun fire. Or if the blast range would help the ki-43 while straffing troops. Im sure any effect would not be huge,as even the 37mm on the p-39's blast range is well....very limited. However i also question if the HE ammo was used in a pure HE form or if they slipped some ap & copper jacket round in the belt as well. If that is the case it would just become a low grade lower damage .50 cal bmg.
