I think you're right Robin. In essence one size does not fit all, unfortunately.

Just for information, my D grade was ordered February 21, 1917 and the order specified "RH 1/2 choke, LH full. The hang tag, dated March 6, 1917, shows the gun was targeted at 40 yards using nitro powder and no. 7 Tatham shot. Results were 230 pellets Right and 274 Left. Tatham's no. 7 shot had 374 pellets in the 1 1/4 ounce specified load giving approximately 60 percent right and 73 percent left. When you have all the information--order, tag, and early shotshell data, it's easy to figure out how/why Parker targeted your gun. One last point that I never noticed before--the tag states "brass shells should never be used with Nitro Powder." I think Parker was concerned that reloaders would use their volumetric black powder dippers when reloading brass shells with nitro powders.

Just noticed that I had given most of the choke data on my D earlier when this thread was first started. Sorry for the duplication. Bill Murphy, I am blaming you for this Jeff Kuss styled brain fart......