[Southpaw]

Question is when did shotgun manufacturers get to a standardized method of measurements of choke based on constriction and not by pellet count?

As example years ago went halibut fishing in Alaska. Wife, dad and son tag teamed and caught a barn door. After shooting it a couple of times with a 410 they wrangled it on board and measured it. They said it weighed 198 pounds give or take 2 pounds. Seems after about a 30 year study with thousands of fish measured and weighed they could estimate a fishes weight within 2% accuracy.

So in early 1900's when did they start just calling things choked a certain way instead of doing the pellet count after years of testing. Maybe the Trojan was the first gun in the Parker line to do this.

Tom I agree you may never know if gun has slightly changed a point or two on choke constrictions due to wear. Also as alluded to with less shot deformation occurring in a modern load the gun may shoot tighter. As long as it patterns around what your shooting and looking at I think it is what it is since I know you aren't going to change it.

BTW I have a Parker VH 16 that think is full and full originally. Right barrel I think is slightly more open after use and it is like an improved modified. Don't think it came that way from factory and fairly certain that gun was not reamed but I think years of shooting that right barrel first has maybe opened the gun a few points. BTW it is well worn but taken care of as well and most of the checkering is very smooth and I like it that way.