Before we continue our discussion about shotgun patterning, I suggest you review last week’s post at http://www.montanaoutdoor.com/2015/08/patterning-shotguns-with-colonel-smoothbore-2/.
Okay, now let’s look at our 2 ten yard patterns. These two should be nearly identical and centered on the spot we put in the middle of the paper. Depending on the choke you used your pattern will be about the size of a baseball (Full, IM, and Modified chokes) up to the size of a grapefruit (Cylinder, Skeet, and IC chokes). It should look like the pattern on the black target. If your shot pattern is more than a couple inches left or right of center, shoot again, and recheck the patterns. If you are low or high by a few inches but vertically centered, you are probably in good shape and will be able to adjust your sight picture after we look at the patterns at the longer distances.
Next, the 30 yard patterns; I really like this distance as it gives me a good picture of pattern density at a very common hunting range and also a highly useful clay target distance. In addition, I can get a really good comparison of point of impact (POI) location in relation to my point of alignment (POA). You might be a bit surprised at how much the shot spreads out in just another 20 yards from the 10 yard pattern. Find what appears to be the center of the pattern and draw a circle with a 15 inch radius around the pattern. Your pattern should be full and even throughout the 30 inch circle like pattern 1. If your pattern looks like pattern 2, full of what we call “holes” such as you see around the center; well, it’s a problem. You will need to do some more patterning work.
There are a few simple remedies for pattern “holes”. It is important to understand that similar to rifles and house cats, shotguns can at times be a bit finicky about their diet. A load that one gun “likes”, another might “hate.” Next week we’ll discuss some of the things we can try to get our shotgun tuned to deliver full and effective patterns. Until then, be safe and good shooting.