I believe that he is reffering to the shooting of game birds by the average shooter ie. if you need a lot of choke you should not be shooting at the bird. He uses 05 and 15 in his hunting guns, I have read.
I myself am not a great long range shooter and when I do hit one at great distance I have a hard time finding it. I seem to be more successful on quail when I avoid doubles and concentrate on one bird from shot to retrieve.
If one is hunting upland game birds in the East I cannot see much need for any choke especially on planted birds and if you hunting blue quail in New Mexico, you are not going to find very many of them if you need a full choke to hit them.
As for clays you can do pretty will with IC on any of the standard clay target games even 16 yard trap.
I enjoy MMc's writing as he makes us feel as if we are there in Scotland shooting drven grouse wearing the fancy vestige and possessing the required accutrements for that pursuit. We all read more for entertainment than information.
