While the 20 ga. is often a favorite for upland game, mostly I use a 12 due to the open country,and number of loads available for it..One of my very favorites is the old field load of 3 1/4- 1 1/4 -6's..But for sage grouse, that load in 4's or 5's is excellent..also for roosters..but on my last trip for huns and chukar, I had some old handloads with the same recipe, but loaded with number 7 shot..on those smaller birds it did an excellent job..
I just put in a light modified choke in my Rem. 870 Special Field, it should be about perfect for all around hunting..what are your favorites..

I use PMC 2-3/4" heavy field loads of 1-1/8oz #6's in my 16ga for Roosters and Chuckar although I don't chase Chuckar very often these days.
For Grouse, Quail, and Huns I like Federals 2-3/4" 20ga Heavy Game Loads with 1oz of 7.5's.
Don't remember the Fed's Dram Equivelent (2-3/4 IIRC) but I know the 16ga PMC's are 3-1/4.
The 16ga is an OU, the 20's a SXS, and both are choked IC/Mod.

Don't reload for Shotguns but I have enough of both loads "hoarded" to last my lifetime and then some. Matter of fact,,, I just shot my first true Double of Roosters yesterday with the 16. If that keeps up, I might have even more ammo hoarded than I thought.

I like Fiocchi golden pheasants, 1 3/8 oz. in 12 ga., 1 oz. in the 20 and 7/8 oz. in a 28 ga. IC/mod. chokes in an o/u. I have had good, clean kills with #6 shot on everything from Quail to turkeys.

This is my fav B&P Classic 16ga Load

Normally use #7s but sometimes switch to Fiocchi Golden Pheasants for last season roosters.
My old double has been opened up and is essentially choked Skeet 1 and Skeet 2. In my M12 - 16ga I normally use IC or Mod Briley tubes.

If you reload, 28g of 7625 in a AA hull with 1 /4 oz of hard 6's patterns very tight because it is a low pressure load with little recoil at 1300 fps.

I like my handloaded 1 1/8 oz. #5s out of a 2 3/4" 12 gauge at around 1300 fps.

I shoot 16 ga guns mostly, and mostly for our prairie birds - huns, sharptail and pheasant, but some forest grouse too. I hunt with pointing dogs. I could do it all quite happily with IC. / Mod chokes and 1 oz of hard #6s at 1250 fps.

Keith, what wad do you use? The AA12? Thanks!

I like an ounce of #7 shot at around 1,300 fps out of a 12-bore. A 2 1/2" shell is all that is required for this. Mine are loaded by Lyalvale.

I run IC/LM most of the time but will drop down to SK1/IC for quail and grouse.

All around would be 1 ounce of 5s or 6s in a 16 Gauge and the choke would be "Modeefied" if I had a British accent. Will bend with an IC for Ruffed Grouse, but don't worry about it all that much.

The more I hunt the less I like small shot for the uplands. Heretic to the Dove, Quail and Grouse traditionalists who are not willing to change, but I've found bigger shot just knocks them down better for me.

battue, interesting..5's have been my favorite for years..although with a bit more shot either 1 1/8 or 1 1/4...and the modified choke would be the one I would pick if I were limited to one choke..6's are also a top pick when I get to do some serious dove shooting..Next time I go to Az. for dove hunting, I am going to load 1 1/8 oz of 6'S..Maybe next fall..

Did some serious work a couple days when I was on with 6's in a hot Dove field. More than a few head flops that gives that sweet curve to the ground.

Pheasants/Grouse early I like 1 1/4 lead 6's out of my 12ga
When I used more lead I loaded 29.5 WSF with the WAA12F114 and W209 in a super X hull. Mod choke.

Late I like 1 3/8 lead 5's best all around load there is.
The fiocchi golden pheasant is the best factory I have used. Used M, IM, and rarely a Full choke real late in the year.

Unfortunately most all our public lands require steel shot for upland birds. I like to run 3" 1 1/4 #3 steel, #2's later. Early season you can get away with #4 steel, but I find #3 better. The blackcloud stuff is nice but not necessary. I'd probably opt for the "Hevi metal" #4's (not hevi shot) if I wanted to pay $20 for a box of shells.

For Doves I favor my 1 1/8 Handloads with lead 7.5's

Modified in the pump guns, I/C - Mod in O/U.
I shoot Federal Premium 4&6, cause I have a crapload of them.

Federal 1 3/8oz 1500 fps #5s out of a modified choke kills the vast majority of my birds.

My main BP cartridge load is 3 drams of FFG , 1 1/4oz of 7 1/2 in a cylinder bored hammer double.
16 gauge is 7/8oz of nickle 7 1/2"s going about 1,300FPS.IC/MOD chokes
20 gauge is used so seldom I can't remember , but it's 4756 and a 7/8oz load of nickle 7 1/2" at close to 1,400FPS SKT1/IC chokes
I also use 30 grains of H110 and 7/8oz of nickle plated 7 2/2 in my 28 gauges - IC/mod in my fixed choke guns.

I know, I'm boring!!
Cat

I don't have one favorite combination I use for everything.
For instance, for Blue Grouse in the back country, I like my 28 ga., 870 Remington with a IC choke, and 3/4th's an ounce of 6's or, if the Mountain Quail are common that year, I might use 7 1/2's for both.
Gambel's Quail, however, I prefer my old SKB, O/U, 12 ga. with heavy trap loads, 7 1/2's, with it's modified and full chokes. That's because I half of my shooting is beyond 30 yds. with them whereas I never do with Blues or Mtn. Quail.
Other game falls somewhere in between those two extremes as a rule. E

I used to use #6s w/full choke (fixed) for pheasant and grouse. The past couple or so years I have taken up duck hunting again. Most of the places I hunt upland game are in close proximity to waterfowling ops. So, to take advantage of this, I have gone to a 12g BPS and i/c choke. I have been working with Black Cloud this year in #4s for everything, last year and the one before, I shot #6 Hevi-shot with great results, albeit expensive.
Strictly grouse and I often shoot a 20g w/#6 or 12 with 7 1/2s.