I can see no disadvantages in running the O/U . It's really like having 2 guns in one.
The spreader is supposedly a cylinder choke with helical rifling to spin out the shot to have it open the pattern quick.
With the 2-3/4 #6 that I wanted to shoot in the close range barrel the pattern with the spreader choke was a 15 yard choke at best. I was really looking try and split the difference with the two chokes so opted for the .670 and .720 option which worked out exactly as I wanted. I just happened to have those chokes on hand as I used them on other brownings. The .720 is a pure gold waterfowl choke and is dimensionally outside the same as there turkey chokes which matched up well.
I see from your report that the spreader choke performed much better for you with the 3rd degree load, which makes sense as it uses the flight control wad that seems to perform really well in open chokes in all of federals loadings. That wad is holding your pattern together better than the standard wad I put through mine.
I'm not done with the spreader choke just yet. I have an Indian creek in .665 as well as an patternmaster anaconda in .670 to try in the future as well as several boxes of 3-1/2 inch 3rd degree that I have yet to try at all.
Once I found my currant set up to be adequate I stopped testing and hunted it. I am interested however to try different combos out to see if I can improve on the current set up.
I won't be testing anytime soon but will try and post the results when I do. Maybe I will resurrect this post in the future with the results as they are very specific the this platform.
By the way during my initial testing I also ran a pure gold .680 and a .696 . The .680 was slightly beat out by the .670 , still very huntable however and the .696 was a little tighter than what I was looking for in the short barrel but again very do able. I haven't written the .696 off just yet. The .696 is a fantastic coyote choke with bigger shot B.B. #4 etc. But that's a whole other subject.
Have fun with your cynergys guys , I look forward to hearing more about them in the future.
