Don't abandon those wildcate. IMO,you just chose the wrong one,especially for your first one. Brass has gotta be an extreme PITA. Bullets,powders,primers,are all the same as ____. There are several non-wildcat wildcats that are great also. 7mm-08,243Win,and some of the Ackley Improved come to mind as does some of the ones that use bigger diameter bullets. By that I'm talkin' >.308".
Also IMO the ranges that most shots are taken at does not equate to a long range chambering. However maybe a speedy one could/would help. The ranges that you will shoot at night is limited by your NVD or thermal and by the need to take a steady rest. Having to shoot from a completely static position is great,however if you move around alot,as we do here,your only rest will be a shooting stick and sometimes a tree. Some of the shots are strictly offhand.
We use 6.8SPCII's or sometimes a 300BLK. If you desire something "bigger" you could go to a 308Win with an adjustable gas block and using H4895 powder could load down by 60%. Then you could up the weight of your bullet to >150gr and move them at 2000-2400fps. Just as long as you picked the right bullet that would open at the reduced vels,which there are quite a few of. Some of the ones that we use for 300BLK would work great at those speeds.
Wildcats are great fun. I have pretty much stuck with the AI's because the brass is so damned easy to make. YMMV --- pruhdlr