Variances in chokes?

[Mike Stahle]

So what your saying is Parkers were not a cookie cutter produced gun.
So about how many times was the average Parker pattern fired and honed
till they had it right? 40 yrds. was mentioned as the patterning range, what
Size shot did they use in this test patterning?

[J.B. Books]

When it comes to choke performance there were no cookie cutters, at least no untested cookie cutters. A PGCA letter may give you information on what the chokes were to be and sometimes they contain information regarding shot size and shot weights used. 12ga guns were often patterned with straight no. 7 shot.

Choke performance is one of the great joys of shooting a Parker in the field.