One argument in favor of short barreled guns for grouse and woodcock is that you're less likely to hit a tree with your barrels. I've hit plenty of trees when trying to get off a shot at grouse or woodcock, but seldom with the last couple inches of the barrels. The extra weight you add when going from a 25" double to a 28" double isn't more than maybe 3 or 4 ounces (depending on gauge), which isn't much. I'd expect one reason short barreled guns have been popular with grouse and woodcock hunters goes back to the pre-choke tube days. If you wanted an open choked gun, it came with 26" (or, far less frequently, 25") barrels. 28" gave you M/F. Talking what the manufacturers gave us, unless you ordered something special. And IC/M (or something even more open, although that was the very typical combination offered) is indeed an advantage for woods birds over M/F.
I recently acquired a Brit 28ga (Wilkes) with 28" barrels and very little choke. Had to add a slip-on pad to give me a little longer LOP. Tried a few rounds of skeet, figuring that at just over 4 3/4# she wouldn't be real good on targets. Have surprised myself with a couple 23's. Doubt she'll end up my go-to grouse and woodcock gun, but I expect she'll be with me more often in the woods than I'd anticipated. Lovely thing for one-handed carry in the thick places.
