Jonny,
May I make a recommendation?
Since your issue seems to be mainly your ability or inability to mount the gun quickly / efficiently, how about focusing on practicing your gun mount at home? You can even wear the same clothing you would when hunting. In the carry position you would normally use when hunting, practice mounting the gun to your shoulder whiLe focusing on an object across the room. Do this deliberately at first until you get muscle memory working then if need be increase the speed a little. I think you will find that if you do this every night for a couple weeks you will find it to help quite a bit. No need to be excessive maybe 20-25 times a night. Just remember to duplicate as best as possible your normal low gun ready position and step into the shot with your lead foot.
Give it a try you may be surprised. I instruct some of my youth league members at our local Sporting Clays club to do the same.
Oh and be sure you gun is UNLOADED....
Birdshooter: thanks for the message. Have thought about doing this at he clays' range but will practice at home too. I know I don't step into the shot every time! Too focused on the mount and looking at the bird.
I don't have issues at the clay's range, as I can pre-mount and usually shoot in the 34 to 38 range with an occasional 40. To date it hasn't been cold so we haven't been wearing heavy clothing; that's changed now...
Often the mount is too quick/fast and I miss the spot on my shoulder and end up too low or high and the cheek isn't on the stock. If I step into the shot I may reduce this problem. Often I'm on uneven ground, on the side of a hill or other awkward positions, so it's difficult to get into the classic mount position.
I do give the roosters a chance!