Determining original choke constriction

[Pa SxS]

From what I've seen, Parker didn't use 7 1/2 shot until much later. They used primarily 7 or 8 shot unless the customer specified differently in the order. Shot sizes for 7 shot varied greatly. Tatham 291/oz, NY Lead Co. 278, Merchants Shot Tower 225, Dubuque 323, etc. So you can see nothing was standard in the early days. Since most of the time the LH barrel was choked full from the company and the pellet count is only 170 my guess is they were using a 24" circle at 45 yards but it's only a guess since the stock book for this gun is missing.

[Jeff S.]

Shame, shame on me. Some of you gentlemen were kind enough to offer input, but I haven't been on the forum for a while so I probably appear rude. Please forgive me.
The serial # of my gun is 151643. It's not one of those "minty" original guns. It's been refurbished, looks great (to me) and I like the way it handles. Both barrels have .015" of constriction. According to the letter that I received from Chuck Bishop (June 6, 2017) the right hand barrel should shoot a wider pattern than the left. Based on the information in the letter, we can all assume that the left barrel has been "opened up".
A logical assumption for a Parker "newbie"such as myself would be that it shipped from the factory choked "mod" and "full" (the letter states 125 pellets right and 170 pellets left). I simply wanted to start learning a little more about Parker's patterning tests. It was suggested that Parker used 1 oz loads of 7 1/2 shot which would mean roughly 345 bb's per load. If that was the case, Parker must have used a circle smaller than 30", or a distance greater than 40 yards.