RAcaseal is a weak class ATP-wise (along with RAmarl), especially when low level (so let's say pre 120-150) because RA has awful base ATP.
For starters, your ATP is probably like 800-900 (or even less) at the moment (assuming that 8x is accurate). That's not very good at all, you're going to need to eat power mats or use power units to get that up. Try to break 1,000 as soon as you can (while still having good ATA, like 210+), and obviously try to get max ATP as soon as you can, because with 1175 ATP, you're still a little on the low side compared to the other Hunters and Rangers.
Furthermore you need the right weapons, this is stuff like:
Charge Vulcans (or some sort of Charge Mechguns)
Dual Bird for solo / if your ATP is still too low to use Charge well
Charge Arms
Spread/Berserk Needle for solo / if your ATP is still too low to use Charge well
Heaven Striker (Charge Raygun works for a bit but Striker has a lot of ATP)
That is pretty much the majority of what you'll need, although there's extras of course such as Baranz Launcher.
If your damage with those weapons feels too low, you really need to get your ATP up more. That ATP is what will give you most of your damage, along with some sort of Shifta of course.