Parker letter and Pattern's stated?

[Kevin McCormack]

You need to know the weight of the shot charge that was used to pattern the gun. This will be recorded in the Stock Books. Then calculate the total number of pellets in the load used (e.g. 1 oz. = 235 etc.), then compare the ratio of pellets in the 30" circle to the total number of pellets in the load. This percentage will give you an idea of how tightly the gun is choked; e.g. 70% Full, 45% Modified, etc. Of course the most accurate measurement is the ratio of the diameter of the barrel at mid-bore compared to the constriction as measured at the muzzle in thousandths of an inch. This ratio is much more representative of true choke boring since it relates muzzle constriction directly to mid-bore constriction. Stop by our table at Chantilly this weekend and we'll have a measuring fest from .410 to 4 bores in play.

[Charlie Price]

I now only vaguely recall reading about it, but I believe shot sizes varied with the maker in the old days. One maker's 6 might be the same size as another's 8, for instance. Somewhere there is some data on the old specs. Pellets per ounce may be a variable in the old records. Charlie