I agree. Even after years of hunting and clay target shooting, my Parkers feel and look like they did when they came home. A couple of years ago, I found a PH grade 20 with Laminated Steel barrels that will be quite the light bird gun.

Bill ,It sounds like a great find ,I really like my little PH 20,it weighs in at 5Lb,14 Oz. almost what my 28 Ga ,weighs " 5 Lb. 12 Oz.", really nice to handle in the field ,especially nice in the thickets and grapevine tangles . Carry her all day and never really notice it !I have been shooting RST Premium # 6 shot for Pheasant and #7 1/2 for Grouse and Woodcock !

Aerodynamics of Spheres
 

There is a table of pattern density attached. It is gauge independent, based upon the aerodynamics of spheres, the initial charge weight, using 7 1/2 shot. and the percent of the initial charge in a thirty inch circle. Note that 1 ounce at .5 (50%), 7/8 ounce at .6 and 3/4 ounce at .7 are about the same at 40 yards. It would be necessary for the 1/2 ounce to pattern 100% to equal these.
The 1/6,1/3, 2/3(misprint should be 1/2) and all columns refer to the standard deviation, based on the mean number calculated from several patterns. That is 1 shot in 6 contains less than that number; 1 shot in three contains less than the second column; one half contain less than the mean, and all shots less than the last number.

Best, Austin