One in a row....

I'll start this post by saying that I am not an expert on patterning shotguns. If you want expertise, buy Bob Brister's excellent book "Shotgunning: The Art and the Science." Bob literally shot and analyzed hundreds of patterns, and even talked his wife into towing a 16 foot long target board with the family car while he shot at it to better understand the effects of shot stringing.

I'm not that dedicated. (And neither is my wife)

In my opinion, the only way to really tell how any given load will perform in any given shotgun is to shoot that particular load in that particular shotgun a lot. Patterning, to me, is simply a shortcut that allows me to get a quick snapshot of how a load might perform. Patterns should not be used as the only tool to decide what load to use for a given situation........unless that situation happens to be shooting at paper targets with circles on them from a fixed position. Unless you can convince your wife to tow a target frame behind the ol' family truckster for you, patterning is done in a static environment. Shotgunning is dynamic, not static, therefore testing in a static environment does not tell the whole story. It gives you an indication of what might happen, but nothing more. To really understand what will happen, you need to actually use the load in question in its' actual application under a wide array of conditions. Having said that, I still think that patterning is very necessary simply because it will help you narrow the field of choices down to a select few that have the most potential.

My testing procedure has three phases: chronograph testing, patterning, and long term evaluation. The results of the chronograph testing on the first four loads I tested (there are 12 more waiting to be run over the chrono) were posted a little while back. The chronograph answers three questions for me: 1 - Is the load in the velocity range I want? 2 - Is it consistent? 3 - Is the load safe for continued testing? Of the first 4 loads, only 3 of them passed the test. Load #3 was below the lower velocity limit for my purposes, so it was eliminated from further testing.

The patterning method I use is a little different from what you see everywhere else. The "commonly accepted" method of patterning is to shoot at a great big piece of paper at a distance of 40 yards, draw a 30" circle around the area of the pattern where the pellet strikes are the most dense, count the number of pellet strikes in that circle and divide that number by the estimated number of pellets in the original load. I have several issues with this method:

First and foremost, I don't shoot at 40 yards. I could care less what the pattern looks like at 40 yards. I want to know what is happening at the distances I shoot at. I shoot very quickly, so my shots on singles targets are usually in the area of 32 yards or so. My current handicap is 26 1/2 yards, so shooting at the same speed results in a typical handicap shot of around 42 yards. Two yards may not seem like much, but as I'll show later it makes a huge difference.

Second, the common method is based on percentages. Percentages don't break targets or bring down birds....pellet strikes do that. The percent measurement will give you an idea of how efficient a load is, but it has little to do with the real world performance.

Third, the common method allows you to draw the 30" circle wherever you want after the shot is made. Sorry....I can't move the target into the pattern after I take the shot, so this method doesn't work for me. I want to know exactly where the point of impact is in relation to the point of aim and the distribution of pellets below, above, and to the sides of the point of aim. Some folks may not have thought about it before, but velocity affects point of impact in shotguns just like it does in rifles and pistols.

Here is how I do it: First off, I don't use a 30 inch circle. I use a 28" square. Why a 28" square? Because that is the size of a 200 yard rapid fire rifle target, which is readily available at my range. Yes, the area of a 28" square is more that that of a 30" circle, but please remember that I'm not working on a doctoral thesis here....I'm looking for hints and indications. If the pattern isn't good on a 28" square, it probably won't be good on a 30" circle either. I start by shooting 5 shots into the berm to warm up the barrel of the shotgun. My particular shotgun always throws the first shot or two about 40 fps slower than all the rest. Once it's warmed up it stays consistent, but I know that the first one will be slow. After the 5 into the berm, I run 5 shells from each test bath over the chronograph at a distance of 10 feet. Don't lecture me about needing a larger data set to get accurate measurements....I know all that. Please remember the "hints and indications" rule. Five is enough to get an idea of how the load will perform. After the 5 chrono shots, I place a target frame at a measured 32 yards and fire one shot from a rest. Point of aim at 32 yards is a 6 o'clock hold on the black portion of the aforementioned 200 yard rapid fire target, simply because I know that my gun throws high at that range. (It's supposed to do that....it allows me to shoot rising targets without having to cover them with the barrel) I then take down the target, write the load information in the lower right corner, staple up another target and proceed to the next load. After all "short range" loads have been patterned, I move the target frame out to a measured 42 yards and repeat, this time with the point of aim at 6 o'clock inside the black area.

Those of you who are still reading may have noticed that I only shot 1 pattern with each load and are getting ready to lecture me about data sets again. Don't bother. Hints and indications, remember? If the pattern looks really ragged or if I pulled the shot off center I'll shoot another one. This is a guide. A snapshot. Don't be so uptight.

After all the loads have been patterned for the day, I take the targets home, open a cold beverage, and start counting itty bitty holes. The 200 yard rifle targets have these really handy hash marks that divide the target area into quarters, so I count the pellet strikes one quarter of the page at a time, marking the "quarter count" in the corner of the quarter. Add them up when I'm done and I've got the total pellet strikes on the 28" square. Divide the total strikes by the area of the target (784 square inches) to get pellets per square inch. Multiply that number by the area of a standard clay target (14.19 square inches) and you get a rough measurement of pellets per target. I say "rough" because the distribution of pellets within the target area is not uniform. Hints and indications.

I've never seen anyone else work with "pellets per target" but it seems like a good idea to me. It also removes any of the percentage confusion that can arise when switching between shot charges and sizes. Which is better, 54% of 1 1/8 ounces of #8 or 73% of 1 ounce of #7.5? They're actually within 3 pellets of each other. Pellets per target gives me a quick way to measure possible effectiveness without having to mess around with percentages.

After all the itty bitty holes are counted it's a simple matter to enter all the data into a spreadsheet and let Mr. Excel do the math for me. Standard deviation, max and min velocity, pellets per target, all the good stuff. Loads are ranked high to low by pellets per target at each distance and that information is bounced off of the chrono data for velocity and consistency.

All this just points me in a direction.....it doesn't tell me how far the road goes. The top contenders from the previous testing are then put into the rotation for long term testing. By long term I mean at least 1000 shots fired at actual targets in registered competition. The scores are then averaged and the load with the highest average wins. I should have the final answer sometime next year.

Pattern data coming up next..........

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// posted by Len @ 1:15 AM