.410 factory chokes and choke tube constriction are all over the place in a .410. Take all charts with a large grain of salt. The only way to know is by patterning them. I’ve seen Full chokes anywhere from .013 to .027”.
My uncle had one barrel choked so tight in his little .410 double, at ten yards it was at most 4 - 6”. Hit a late quail, with that and it is a pillow fight. That was until I tried a load without a wad. Then it made more sense. His shells 60-70 years ago had no wads to protect the shot. With a wad it was unusable but for anything past 25 yards. It would crush a high four at Skeet. Without it was still tight but not unreasonably tight. Then his choice of load made sense.
