We've had a dramatic cool down in Southern Illinois over the last several days. We've approached and in some cases beaten long-time records for low temperatures. The air has also been very dry. That's exceptionally unusual for this area this time of year.
I wanted to take advantage of this these low temps and dry air to pattern some guns for myself and some chokes and barrels for several readers. These temperatures more resemble hunting temperatures in the fall in many places, so it's a real opportunity to see how guns pattern under those conditions.
I was able to spend a good portion of 3 days at my range with a variety of guns including a BPS, SBE, Mossberg 930, a 20 gauge Mossberg 500 and a couple of Remington 870s in both 20 gauge and 12 gauge. I ran a number of different choke tube brands and exit diameters through those guns but used Hevi-13 shotshells in all of them, since that's what I use both for hunting and in competition and it's what my readers requested I use with their chokes and barrels.
Whenever I perform patterning services for a reader, I always ask about his cleaning procedures. I want to pattern the gun in the same way that he would so that when he shoots that same barrel with a given choke tube and shotshell, he's more likely to duplicate the results that I see.
My personal procedure begins with a good “deep cleaning” http://allaboutshooting.com/articles.php?tPath=39 of the bore. Then I shoot at least 5 rounds without any cleaning between shots to see if my barrel and choke combination like to be squeaky clean or a bit fouled. That's really the only way to learn how your gun shoots best. Some of my guns like to be squeaky clean and others like a fouled bore much better. In reality, for hunting purposes, most guns will shoot adequately either way but if you're looking for maximum numbers and evenness of your patterns, a bit of research can be very beneficial.
My range work again demonstrated that the differences in choke tube design, internal geometry, determine the exit diameter that will work best for a particular choke tube. One example will illustrate what I mean.
One of the guns that I shot was a BPS with a 28” barrel and a 3” chamber. I had a variety of JEB's chokes including a .645, .650, .655 and .660. I also had Wright's chokes in .650, .660 and .670 and the SSX in .643. These are very different chokes in appearance and design. The JEB”s is ported, the Wright's is non-ported and the SSX has “false ports” forward of the true muzzle. The internal geometry of the 3 brands is also very different.
Cutting to the chase, the .655 JEB's, the .650 Wright's and the .643 SSX all produced dense and even patterns at 40 yards with the Hevi-13 shotshells.
I used a number of different chokes with the BPS and with the other guns to determine which combination produced the most dense and even patterns with each of them and while each gun may be slightly different, there are common traits to each of the brands.
I would encourage every hunter and shooter to take advantage of changes in weather and pattern their guns. It really lets you see how temperature and humidity can affect how well your gun patterns. You may be surprised by the results.