Any advice? I'm planning to work up a 1050 fps load using 230 grain projectiles, power pistol and starline brass. My hunch is that it isn't dangerous for the oly arms carbine.

This is an integrally suppressed upper with a ported 10 inch barrel, hahn mag block and heavy buffer.

Advices? Signs I've gone too far?

you should have no problem, i have shot .45 Super through my 16inch Oly. with 185 gr Golden Sabers loaded with Power Pistol clocking out at 1700fps

Paul

Wow, a golden saber designed to expand at 900 fps going 1700 fps would wreck someone's day.

I noticed some inconsistency in my 100 yard impact point from session to session. I ended up chronying a bunch of the off the shelf stuff and found that it varied from 750 to 930 fps. Impact points would vary by as much as half a foot at 100 yards.

Wolf and WWB were in the bottom of the shit tier in terms of velocity (700+ fps), though wolf was surprisingly consistent.
I still don't use wolf in the carbine because it's dirty as hell.
Remington and CCI were relatively high velocity, closer to 900 fps.
I got some denel pmp and some MFS to try, I'll see if they're any hotter. I'm doubtful.

But the basic idea is that I want something that is consistently 1050 fps or so because I'm tired of the bullets hitting all over the place whenever I switch from one box of ammo to the next. I also want minimum drop without breaking the sound barrier.

Power pistol is a great powder for these loads. Be sure that you use 45 super brass.

I've been working on Hornady 230 grain XTP loads, pushed with Power Pistol in Starline 45 Super brass.

I've maxed my loadings out with 9.8 grains at 1410fps at just over 1000ft/lb of energy.  I saw pressure signs at 10.0grains, so obviously backed off.  This is out of a 15.5" barrel.

I was also testing loads with HS-6 before I found Power Pistol in stock.  I saw just under 1300fps before shit got a little hairy with the pressures.  It seems HS-6 was decent before pressure signs, but the velocities became erratic, and it was pretty snappy when I started to get closer to the extreme end of the spectrum.

HS-6 is supposedly ever so slightly slower burning than PP, but the loads don't lie.  It looks like PP is the way to go for 45 Super/ACP out of anything longer than pistol length barrels.