That is almost spot on to what I use. I use 18 for 16's, 32 for 27 yard, and 28 for league HDCP (usually 23 or 24).SecondChance,
Assigned yardage + 5 thou.
16 yards + 5 = 21 thou. So I would use a 20 thou choke tube
23 yards + 5 = 28 thou. So I would use a 30 thou choke tube
Imod is my favorite for 16-21, then move to FI was at the club last night and the topic of what choke came up for what yardage. I told them that I have shot Mod from 16-23 most my life till the IM came out. I now shoot it almost exclusively unless cold or windy and bump it up to full.