Cooperative North American Shotgunning Education Program (CONCEP)

February 13, 2009 by admin

By Kevin Hayer

Last spring I was invited to a CONCEP nontoxic shot seminar presented by Tom Roster and hosted by the N.D Game & Fish Department. CONCEP is short for Cooperative North American Shotgunning Education Program which is an international education and research program. CONCEP is supported by multiple Game & Fish agencies including North Dakota Game & Fish department, US Fish and Wildlife Service and a host of others. Tom Roster has been researching steel shot since the beginning and has no known peers on the subject. During this seminar participants received a copy of CONCEP’s Steel Shot Lethality table for waterfowl. Years of research and testing were used to come up with this table. It determines shot size needed to penetrate different size birds at different ranges. Tests were conducted by the X-raying and dissecting of waterfowl that were harvested with certain loads at known ranges. Records were also kept if the birds were killed outright or wounded. This table lists most effective shot size, minimum load weight (oz), minimum pellet count needed at a curtain distance, and most effective choke for birds from teal to honkers. Let’s take geese for example. For medium and small geese at 40-50 yards the most effective steel shot sizes are #2 and BB, and a minimum shot charge of 1 1/8 oz. Also your gun needs to put 60-65 pellets in a 30″ circle at that range. The suggested choke is modified.

It is our responsibility as ethical sportsmen to harvest our birds cleanly with the least amount of wounding as possible. To do this, we need to practice shooting to improve our shooting skills and use the best choke and load combinations for the job at hand.

Let’s take a look at steel shot loads. The current trend is that speed kills. What cost are we paying for this speed and what are we really gaining? To get these high velocity shells we have to give something up. What we are giving up is the shell’s payload (pellets) so there is more room for powder. When shooting at a bird and trying to harvest it cleanly at longer distances, it is much easier with 1 ¼ oz. of pellets compared to a 1 1/8 oz. load. This is according to the CONCEP steel shot lethality table, using loads with velocities between 1225 – 1450 feet per second. We are also dealing with round balls and not bullets with high ballistic coefficients. For a round ball to fly at its best, it needs to be as smooth and round as possible. That is why we should buy shells that have quality pellets. Be fore you buy a case of shells, buy one box and cut open a shell and inspect the pellets. If they don’t look round and smooth, they probably won’t pattern well either, especially at longer distances. I am not saying you can’t kill honkers at 25 yards with 7 1/2s and a .410 but that doesn’t make it a good combo either.

Now I would like to discuss chokes; what a choke is and what gives a choke its designation. “Choke” really means constriction or lack of it. As a general rule, the more constriction the tighter the choke, and the less constriction the more open the choke. A choke’s constriction is measured in thousands of an inch. A choke gets its designation by how many thousands of an inch its taper is smaller than the barrels bore diameter. Almost all currently made shotgun come with screw-in chokes. Most shotguns come with the three most common choke designations: Improved Cylinder (IC), Modified (Mod), and Full. A lot of tubes come with two designations, one for steel and one for lead. In this article, when I am discussing a certain choke I will be referring to lead designation. The standard bore diameter for a 12 gauge is 0.730 thousands of an inch. Now let’s go back to those standard chokes and there standard amount of constriction (Improved Cylinder 0.010, Modified 0.018, Full 0.036). So if our bore diameter is 0.730 thousands of an inch, our improved cylinder should measure 0.720. This brings us to one big problem that bores vary a lot. Last week I was discussing chokes with a customer and we decided to measure the bores of his three shotguns, all made by the same manufacture and model .The first had a large bore 0.740, the next 0.730, and the third 0.726. We then screwed in that Improved Cylinder choke that measured 0.720 in the first barrel that had a bore of 0.740. That combination would give you a tight modified (0.020) pattern. We then tried that same choke in the gun with the 0.730 bore. The result was a 0.010 of constriction and have a real Improved cylinder choke. Over the years, I have measured thousands of barrels and chokes and this example is the norm and not the exception. The only way to know for sure what you really have in regard to your shotguns bore and chokes is to have your local gunsmith measure it for you. Most gunsmiths will do this without a charge.

To know how your gun and loads will perform you will have to shoot some paper or “pattern” by using the CONCEP Lethality table as a guide. Look at suggested shot sizes and loads for a specific bird at your intended range and see what choke will meet needed criteria according to the CONCEP table. It’s the way to learn your guns limitations. Once your weapon makes the grade can you? To get a copy of CONCEP Steel Shot Lethality table contact the N.D Game & Fish department.