I'm making the switch from a 10-gauge to a 20-gauge this year and so yesterday I tested three chokes to see what worked best.
Gun: Remington 11-87 Sportsman, 20-gauge, 26" barrel
Ammo: Apex 3", 1-5/8 oz. TSS #9 (590 pellet count)
Chokes:
.560 – Trulock Federal TSS, F7TREM20560
.565 – Trulock Precision Hunter, non-ported, PHREM20565
.575 – Trulock Precision Hunter, non-ported, PHREM20575
I took two shots with each choke at 40 yards and cleaned the barrel with Butch's before each of the six individual shots. To count, I eyeballed the greatest pellet mass, drew a 10" circle, split that into quadrants, and counted them NE+SE+SW+NW = Total. Temps in the 50s, calm winds.
.560 – shot 1: 64-55-64-69 = 252
.560 – shot 2: 76-66-56-55 = 253
.565 – shot 1: 86-71-101-73 = 331
.565 – shot 2: 73-65-71-54 = 263
.575 – shot 1: 74-52-66-72 = 264
.575 – shot 2: 84-64-55-109 = 312
While I feel all six shots were turkey killing patterns, I'm a little disappointed that no one choke stood out as the clear winner. I did this test in 2020 with my 10-gauge (results on 10-gauge page), one choke clearly won out for numbers and consistency. I was hoping for the same, but don't really feel I got that.
Looking only at the numbers, I'm giving the nod to the .565. In six of eight quadrants, it had 70+ hits compared to four on the .575, and one with the .560. However, the .560 has the most consistent numbers. When looking at the pattern beyond the 10" circle, the .565 and .575 were comparable, while the .560 had many more fliers well away from point of aim.
So... I think I'm going to settle on the .565. Though I'm going to keep to the .575 as I may test #7.5 shot for grins and giggles in the future.
For the other nerds out there who have tried tests like this, what has been your results for consistency of 10" pellet hits between shots? Again, I'm kind of disappointed with the 50+ count swing between shots. But that could be a number of factors like me not eyeballing the 10" circle correctly, inconsistent barrel cleaning between shots or maybe the shotshells themselves (though I wouldn't think so).
Long post I know, but maybe it'll be useful to somebody else.