skeletal snipers in endgame.

I just swapped to skeleton snipers at endgame from reavers when I was able to afford a perfect jeweler orb.

Imo I think its best to go all phys and crit so you need brutality support first over physical +1(until you get to the end) I would drop scattershot for either chain or fork, those two seem to hit targets better. Martial tempo is a must, your tool tip dps skyrockets up with it. Hard to fit before perfect jeweler but check for tooltip dps and do whatever keeps ya the highest. Before the last slot I was running without chain/fork and it was fine since the snipers 1 shot everything.

You need to respec the tree to include minion crit and bonus damage when crit nodes.

For scepter you either need malice or you pick up the winter orb skill to apply critical weakness.

I found Snipers a little awkward around that level. They sprayed damage and didn't really form a front line compared to reavers or frost mages which were really stable when I was undergeared. They scaled really well though as I got more gem levels, support gems, and number of snipers so they kill on the first volleys and clear really well.

They felt more like better support at that level but if you're committed to them, I'd recommend adding detonate dead for clear and/or focussing on the activity ability - it's really strong and fun to play around. You can scale gas arrow really easily (deadly poison, bidding, concentrated effect; comorbidity + scatter shot is great if you have enough slots) and ignite with the dog for the initial kills. You only need 2-3 poison snipers to support: you can add a second sniper gem with physical supports for the rest of your spirit. It gives you a bit more targeted control.

Martial tempo, fork.

More levels. The answer is almost always more levels. They do have a lot of gem tags you can abuse for unique mods on gear/tree.

Go full reavers and a few clerics

Drop physical mastery for martial tempo, the others are correct. Make sure you are keeping pain offering up.

https://maxroll.gg/poe2/planner/2j2cr0q2 here you go, this is what the highest ranked infernalist is running on the ladder. You can also find him on twitch, great guy who responds to every question.

my snipers are level 36 and I run martial tempo - heft - feeding frenzy - fork - scattershot for clearing and swap out the last two gems for fire infusion and chaos mastery when I go bossing. I could do a T4 breach boss with this easily, although normally I do bossing on my other character (frost mages chronomancer)

Honestly snipers feels more like a support minion endgame rather than primary minion type. You can do something like a couple snipers + bruters or reavers, and give snipers corrode for armor breaking on poison to help your melee minions do more damage. If you're super lazy like me you give them Envenom too so you don't even need them to drop the poison cloud to break armor.

The other use is pairing them with Arsonists and/or Hellhound for exploding gas clouds.

Overall tip for minions if their damage feels low is to get as many +Minion levels on your gear as possible though. It scales them way higher than anything else. By endgame you should be able to get something like +10 or more to minion levels depending on how much money you want to spend trading.