Dear Technoid,

You will be pleased to hear that I have finally got around to patterning my skeet gun. As usual this exercise raised more questions than it answered. Being somewhat stubborn however I am pressing on and hope you can help me with one of those pesky questions.

I found that my 12 gauge Rem 3200 with 3 to 4 thou of choke printed on average 62 percent patterns at 20 meters. (21point something yards??) This seemed a bit low to me and the effective pattern seemed not much more than around 20 – 21 inches diameter.

I am loading some lower velocity shells to try to bring a few of the fliers back into the pattern but I was wondering if you could tell me the optimum theoretical percentage for 20 meters/yards to give me the biggest effective pattern so I have something to work towards. ( I guess it should be more like at least 70 or even 80 percent). Oh, this was with 24 gram (7/8oz) loads. I am a little shy of recoil and I can’t use my gas gun anymore(sob sob!). I realize it will be different for 1oz loads (maximum legal in Aussi competition). Perhaps you could tell us the optimum for 1oz as well?

Best regards,

Andrew
Australia

Dear Andrew,

You are going to have to do some interpolating because US information uses feet instead of meters and the standard US clay pigeon at 108 mm is slightly higher than the standard ISU clay. I don’t know which one you use. I don’t think that it will matter too much as what you want to do is to compare loads. Here is what I would do:

Warren Johnson’s most excellent Choke Chooser slide card (see our SR ad section. The device is REALLY helpful in this analysis.) shows that a 1 1/8 oz load of #9s at 20 yards has an effective killing pattern of 21″ from a Skeet choke. A 1 oz load of the same has 20″. It would be reasonable to assume that a 24 gram load (about 7/8 oz) would be around 19″. Warren defines the edge of the killing pattern as having an 80% chance of a two pellet strike or 95% chance of a single pellet strike. I have found that this is a very practical definition in the real world.

Now comes the good part. Warren’s work is statistically as accurate as a computer can make it and very useful as a starting point in analysis. Warren has made certain assumptions (as he must) in setting up his Choke Chooser. A Skeet rated choke is considered to throw a 40% pattern into a 30″ circle at 40 yards. If your Skeet choke actually does perform that way (depends on your barrel, choke and shell), then the rest of the mathematical analysis follows.

Here is what I would do. Your 3200 barrels of .003″ to .004″ are close enough to the nominal skeet choke constriction of .005″ so that you have the right to expect “skeet” patterns. This means that you should be looking for ABOUT a 20″ effective pattern at 20 yards. This certainly bears out your initial analysis.

To fine tune and compare loads, I would simply get a yard stick and, using it as a compass, scribe a 19″ circle and a 21″ circle around the visual center of the shot cloud (not around the aiming mark) of a pattern you have just fired on paper. Count ONLY the pellets in that 19″-21″ ring. Do at least three of each and every shell that you want to compare. I use red resin flooring paper, 36″ wide and in large rolls, for patterning. The shell that puts the most pellets into that 19″-21″ circle will be your best skeet load. It is labor intensive, but simple. It will allow very accurate comparison among shells and guns.

If you don’t think that your gun is performing up to standard , compare it to a gun of known performance using the same shell. Counting only the pellets in the annular ring will save sometime. Just remember to find the center of the shot cloud on paper by eyeball, not by using the aiming mark. Aiming marks are seldom the correct center if you wobble around as much as I do.

If it is helpful, most of the US International Skeet shooters are using 24 gram loads of #8 1/2s and IC (.010″) choke. International clays are physically much harder than the standard soft 108s. ISU skeet also requires doubles on most stations, so they have to choke for that second bird.

Best regards,

Bruce Buck
Shotgun Report’s Technoid