800 rds in 24 years? Don't wear it out now.
So with ball, round nose and perhaps some HP ammunition, you really don't have any problems? Is that what I'm reading? It's not uncommon for Gold Cups to be a bit ammo finicky, especially when new... and to me, 800 rds still qualifies as new'ish.
I have a SS MkIV GC, made in 1992, that would not feed any hollow points but Winchester Silvertips when new. At around the 2K round point (and with a light polish of the frame and barrel ramps), it would feed most anything including Speer "flying ashtray" and Black Talon HPs. As I'm still working my way through a case of Hydra-Shok, I've never tried Hornady Critical Duty.
I was going to ask if you had adequate extractor tension and if the loaded round feed smoothly from the magazine to under the extractor hook... but chances are that's not an issue.
For years the number one problem I had, with Gold Cups that were fit with Elliason sights, was the damn dowel pin at the front of the sight. If your gun shoots 2" at 25yds, then, suddenly goes to 4", then goes completely to hell... that's the sign your dowel pin is going, going... gone.
I finally got smart and made my own solid pin and haven't had a problem since.
I don't know where you live, but I'd track down a known
, 1911 gunsmith (as opposed to any
gunsmith) and just have them take a look at it.