I’ve got a question I haven’t seen addressed before. When I pattern my shotguns, I shoot five rounds at the pattern plate, count the marks, and take the average. Given the Gaussian nature of patterns, that seems like a reasonable way to do it. I don’t believe in fractional parts of percentage points, and never count the number of pellets in a shell (1 1/8 ounces of #8 shot is 460 pellets, and that’s close enough for me), so my calculations are only approximate.
Is there any advantage to shooting one round at a time and counting the marks each time? How do you do it?
Beer open, waiting expectantly,
I have done this one before, but on the odd chance that I have changed or forgotten something, here it is again.
I don’t use a plate for patterning. I just use one to test point of impact. When I pattern I use the red resin flooring paper available at any home supply store. How I set up my sheets depends on what I want to do.
For standard choke testing at 40 yards, I MEASURE 40 yards from gun muzzle to paper. I tape an aiming mark onto the center of the paper and shoot once at each piece of paper. I shoot three pieces of paper for each shell/choke combo I want to test. Five would be better. I don’t to anything more than that at the range.
When I get home I COUNT the pellets in three shells, so that I know what I am dealing with. You might be quite surprised as to how far off from “nominal” some shells are. If you save the information and use the same shell again, you don’t have to do it twice.
Looking at the BACK of the pattern paper (where the shot has made little “volcanoes” in the heavy flooring paper), I guesstimate the center of the pattern. Remember, the aiming point is on the front of the paper, so you are just working with a blank sheet here.
Then I take a yardstick which I have set up like a compass and scribe a 30″ circle, and often other smaller rings depending on the test. I scribe my circles around my guesstimated center (not the aiming point on the other side of the paper) and start counting. Normally, I find it easier to quarter the circle before counting. When I count a pellet, I dab the hole with a Magic Marker.
That’s about it. I make sure to save all my information in a database or notebook for future reference. I also make sure to turn the paper over and compare the aiming point with the actual center of the pattern to find out how far off my barrels are. You might be surprised.
Shotgun Report’s Technoid
(Often in error, never in doubt.)