New Load Data for CHOKE CHOOSER

Ed Note: Warren Johnson is one of our technical writers and brains behind Choke Chooser. We are pleased to include this special Technoid edition by Warren.

Dear Warren:

I’ve been doing a lot of pattern testing and load development to get the “right” loads for me for sporting clays (read into this low recoil). (I would probably be better off practicing…)

My challenge has been to find a recipe for a 7/8 oz. load that uses the Win 7/8 oz wad, WAA12L and other Win. components (primers, powder, and hulls) and travels about 1180 fps. (I think that even though a competitor may have different loads for different target presentations, they should all have about the same velocity…the idea that “I’ll use a faster load for that long crosser so I won’t have to lead it as much” is one more data point that my mind doesn’t need).

The Win. loading pamphlet lists loads from 1325 to 1400 fps. All the other books list loads that require card fillers or use components that I don’t care to stock.

After some experimentation, I found that 17.0 grains of WAAP moves 7/8 oz at 1180 fps…however, since the Win loading book shows 21.0 grains produces 1325 fps and about 7,400 psi, I’m sure this load is off the bottom of the chart with respect to chamber pressure. However, it patterns nicely in my gun. In fact, it produces the peculiar result that at 30 yds with my IC choke the pattern is only about 24 inches where my 1 oz load of magnum #8’s (launched at the same 1180 fps) at the same distance and choke produces a 30″ pattern.


P.S. Is there any hard research on the range that various shot sizes can break targets? I, like you, have read the 30 yard limit on #9’s but I’ve begun to be more skeptical of some of the long-held myths in shotgun and pattern performance…such as the long shot string theory for wide targets at trap.

Dear Technoid and all you other enlightened Choke Chooser users out there:

As you know, Choke Chooser covers 1-oz and 1-1/8-oz loads of No. 9, No. 8, and No. 7-1/2 shot. Unfortunately, because of space limitations (I wanted to keep the device small and handy), I wasn’t able to include 7/8-oz loads. This is too bad, because, PAIRED WITH THE RIGHT CHOKE, 7/8-oz loads can do a fine job on some targets, with substantially less recoil: 32% and 19% less than 1-1/8-oz and 1-oz loads, respectively.

So, in response to popular demand, I’ve calculated values of optimum choke and effective hit circle diameter (inches) for the various target sizes and orientations, at three ranges, for a load of 7/8 oz of No. 9 shot. These are listed below:

Target Size Target Orientation Range
20 Yards 25 Yards 30 Yards
Standard Face-On C/31 C/33 C/33
Half-Turned C/26 S/27 IC/27
Trap-View C/22 IC/22 M/22
Edge-On S/18 IC/18 IM/18
Midi Face-On C/27 C/28 S/28
Half-Turned C/22 S/22 M/22
Trap-View S/18 M/18 IM/18
Edge-On IC/16 IM/16 EF/16
Mini Face-On S/19 IC/19 IM/19
Half-Turned IC/16 M/16 EF/16
Edge-On M/12 EF/12 EF/11

Ranges longer than 30 yards have not been included because the pellet energy of No. 9s is marginal for breaking most targets beyond this range.

As you can see, to give you the best chance of breaking each target, choice of choke is critical for this light load.

Best regards and happy shooting,

Warren Johnson
Shotgun Science

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