formal patterning is done at 40 yards in a 30" circle (except a .410 - that's 30 yards)
but if you take game closer, grouse or woodcock for example - you might want to see what the pattern looks like with the shot you use at the range your average shot is taken- and that might be different for each barrel if you really want to experiment
__________________
"If there is a heaven it must have thinning aspen gold, and flighting woodcock, and a bird dog" GBE
|