Yes, many of Pope's barrels were choked, after a fashion.
Pope's barrels were more of a tapered style tapering from the breech to the muzzle.
Of course, Pope's barrels were designed to shoot long heavy bullets not balls, but many of them used bullets which were loaded from the muzzle. The primed, powder charged cases were of course loaded from the breech.
When I think of "choked" muzzleloading barrels like we use with round balls, I picture the style which has a uniform bore diameter from the breech to about 6-10 inches from the muzzle.
The barrels diameter is "choked" or reduced in size in this last 6-10 inches, a few thousanths of an inch.
This is supposed to give a tighter fit on the patched ball or bullet to improve accuracy.
Like the "gain twist" barrels, there are arguments about the added value of choking the bore but the theory sounds good to me.
As to the ease of creating a choked bore, IMO, it would be rather difficult to do it correctly without some fancy precision hone and precision bore gages (like a special air gage).
If, talking from the breech to the muzzle, the bore ended up being large, then small, then large, then small at the muzzle it would be similar to a "ringed" (or bulged) bore and my experiance with barrels which have been ringed is that they won't shoot worth a dam.