That chart is worth about what you paid for it. With good ammo in the hands of a good shot, the range of a modified choked 20 gauge will shock most people. Well beyond what the chart says.
Good to know and thankful the chart cost me nothing. So, what chart for chokes is better ?
No chart will give much light here, as there are too many variables, as battue alludes above. With cheap bargain basement shells, no choke will adequately compensate in terms of pattern performance.
Choke selection goes hand in glove with pattern performance, and that is the real measure of a choke/ammo combination. For the purposes of this discussion, modified is a good place to start, but you really want to know what the choke does in performance terms. Some factory chokes are also notoriously mismarked - have both constrictions and actually performance that are way off. Browning screw in chokes have this reputation, for example. It is also very common for a gun to prefer a particular load. So there is no hard and fast rule here.
I have a Benelli Montefeltro 12 ga., for example, whose factory chokes perform about one choke tighter than they are marked; it’s modified choke throws almost full choke patterns with all of the ammo I have tried in it.
