The 243 is a great round, loaded with a 100 grain partitions is plenty for elk. Either way you go, shot placement is key so make sure they spend some time at the range.
I have 2, year 1 they were great.
Now the Xb model started to send multiple blank pictures repeatedly. I contacted their customer service and they recommended turning one antennae up and the other down. Now it sends 3-4 check-in pictures twice a day, so not completely fixed. Could be an issue...
Get some good glass….they can bed close you just have to be able to pick them out of the brush they love to hide in. Always look behind you, they will let you walk right by.