Although I've never owned a Churchill gun, I do own a Bernardelli Gamecock 20 gauge with 25 inch barrels. I don't shoot it much anymore because I'm into hammer guns, but I found that on a skeet field I did ok with it if I shot low gun, but poorly if I shot the gun pre-mounted. It was the only shotgun I owned for a number of years. It's lethal on preserve birds and I once went 11 for 13 with it on a dove field, but nearly all those shots were similar to high house station one on a skeet field.

I find that I shoot it better if I extend my left hand (I'm right handed) farther out the barrels than I typically place my hand on a side by side. Not sure why, but it seems to work.