I hunted grouse for the first time with a 16 bore top lever damascus hammer double from the 1890's. Many of the issues discussed here crossed my mind when I gave some thought to my approach for these hunts. At first, I decided to carry the gun loaded, closed, and uncocked. A couple of flushes later, I decided to cock one hammer as the dog went on point. After a couple of muffs, I decided to cock both hammers on point. This was successful, but then there were wild flushes I wasn't prepared for and I began carrying the gun with one hammer cocked at all times. Alomst as soon as I resolved to carry thusly, I tripped over a partially buried single strand barbed wire fence rushing into a point and dropped my gun. Fortunately it did not go off and no damage to the gun. I began to carry it uncocked from that point out and actually switched over to hammerless guns for the remainder of the season!
I did hunt pheasant in SD with my 11 bore M/L double this year. I mention this because it was actually useful to have a non-rebounding lock. I found it much easier to engage from half-cock as a bird flushed than a rebounding lock. Of course pheasants will often give you a second more than a grouse from flush to shot, but I actually did enjoy the muzzle loader in the upland scenario and did not feel hampered by the hammers.
