The only two people I goosed were done so with the 40mm. Practice, son.
If you have two geese with the 40mm that's great and all but that's hardly a proof of concept for getting 50. I think I have 3 on Xbox with the 40mm, but if I project that out it probably takes months of playing to do it.
Still working on PC. The fact of the matter is you need to lobby shop. You need just the right type of noob that isn't running auto-eject, is still aware enough to manually eject, but not aware enough to hit his cloak (all noobs run cloak), and isn't much for altering his trajectory in mid-air. One guy like that you can goose every game. But a lobby full of decent players? Ugh. It's bad enough when they know to cloak, but then you get the trolls that will stay in their Titan to the bitter end, or just hop out normally and get owned on the ground as if that is somehow better than giving me a chance at goosing.
I tried the strategy of running a smart pistol and going for rodeo ejects but that really went nowhere. Those ejects where you end up close to the guy in mid-air just seem way too rare.
I tried the DMR for a while for sniping cloaked ejectors but it just didn't quite work out. I probably hit 10 guys with a first shot but never landed a follow up and a kill. Maybe still a good option for someone with superior aim. I tried the R101C with silencer... but just not quite the killing power, once again going to need better aim than mine to make it work. But, finally threw away the silencer and went extended mags. One fewer shots to kill, and 10 more rounds to spray at a goose? That's just enough for me to get the occasional goose on foot. I had a nice goose this morning on Rise where I was up top hopping from wall to wall, wallhanging, taking titans out with the charge rifle from above, then dropped down to ground level as the guy was ejecting and sprayed him down. Of course that only worked for the one guy on that map. Everyone else would cloak on eject and land outside the map to make use of their 10 second countdown. I mean, I can't blame them, I do the same thing... but it's painful for us poor goosers.