I see it continually on shooting forums 'my bore measures x, my choke measures y', what pattern will it throw?
Well Sir I do not know, I can only take an educated guess because it varies so much dependant on what cartridge you use and what wadding is inside, plus many other factors.
So the real answer to your question is.
" Take the gun and the cartridge you are going to shoot regularly, shoot at the pattern board at the distance that you will expect to be shooting most, and then calculate your pattern percentage". The answer needs to be calculated from the average of a least ten shots, not just one shot.
