Not sure which inertia gun you have. I have a Benelli Supersport. It does handle 7/8 oz. loads @ 1250 FPS plus. I shot those loads in a winter Skeet league with no issue, no matter how cold it was.
I have never tried 3/4 oz. loads in it, but I doubt that they would reliably cycle my shotgun. I dropped the 7/8 oz. loads to 1200 FPS and every now and then it would fail to cycle.
I have tried 3/4 oz. loads in my 16 gauge guns, it was kinda fun but I have no confidence that as the range gets longer, the 3/4 oz. loads break every target I point correctly.