Way too hard to get in active maps
I frequently load into maps only to have the “this map is closing” popup appear literally seconds later. They really do seem to have a bug in whatever code is choosing instances to put us in. Guild halls, especially—twice tonight we all ported to the guild hall at the same time, only to end up in two different instances, neither of which gave the option to move to the other.
LFG rarely works for me—usually when a listing for what I want shows up, it disappears again before I can do anything. Or it just never shows up at all, because no one wants to do the event, because it’s completely ridiculous (TD meta).
I could be wrong, here, but I don’t think killing the Axemaster is in any way needed. At least, the one session I spent in Shooting Gallery (not even getting bronze) was in daytime, once Bongo’s camp was cleared as part of the Nobles chain.
And just this evening I two-man cleared the camp. It was slower than with a good crowd but there was still a lot of time until nightfall. Not enough time, night came when the wyvern was at 1% health, but certainly enough to do some adventures.
LFG is full of taxis to HoT maps, too — though you do need to be looking around the phase change times. http://dulfy.net/2015/11/09/gw2-hot-maps-timer-famme/ will help you spot when those are.