I have a 6 piece set of IM-size chokes for a Browning Invector Plus that were machined for me out of stainless steel on some of the most accurate CNC machinery available. You can't measure any differences between them yet no two pattern the same and each one is repeatable. Have no idea why, just know that's what happens.
There's generally more to chokes than just the constriction. parallel section, taper to parallel, polish, etc. That's why theres not just one choke manufacturer. Why doesn't all toilet paper feel the same? Well, let's not go there!!...
I tested them on paper targets. Even though the outside diameter was pretty much the same, the wrights target had many more pellets centralised... much denser in the middle. I also noticed it shooting from the 21 yard line. When dead on, the targets would evaporate. John
I've found to mic them and know what constriction you are after is most important. If you were to buy an improved modified from Browning, Briley, Hastings and Tru-loc and so on, no two would be the same. They would overlap from modified to light full or full.
I'll assume you are a good shooter(I'm not, I'm just o.k.). A day at the trap field shooting 16yd. targets. I'll assume you shoot a BT-99 with Briley IM extended ss clay tube. In between rounds I slip in the modified version of the same Briley tube, I bet you shoot the same and won't notice any difference. You could smoke the targets the same with both tubes.