Rick, I think you'll find that single-base 7625 or better yet 4756 are as close as you're going to get to DuPont's progressive "Oval" or the Western Powder Company's equivalent that used a different technology. Although both were called progressive burning they might have been better called "slow ignition".
Just as an aside I've read for years now that 7625 can be erratic at cold temps and I wonder if that's because of gents loading to VERY low pressure and having plastic wad gas sealing problems, or possibly some correspondents just repeating what they've read? A few years ago I debunked it at least for myself by leaving a bag of 7625 loaded 12-gauge shells outside overnight in sub-zero temps in the bed of a pickup truck, and shooting 100 of them the next morning on a sporting course when the ambient was in the negative Fahrenheit numbers to start out. They all went off with authority with no perceptible recoil reduction as compared with shooting the same loads at normal temps. The IMR chart showed pressure at about 8000 psi, temp not stated but probably 70-80 degrees in a ballistics lab. Pressure was undoubtedly lower when I shot them that morning on the sporting course.
Lastly, if you shoot 2-3/4" shells in that LCS Long Range/3-inch chamber you'll probably lose about 8-10% efficiency (pattern percentage) at 40 yards. That's with lead shot.
frank
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