Just make very sure that you weigh it. Like most Winchester ball power it takes a much smaller bushing than most flake powder does. It is not going to matter much if you use Remington hulls, AA compression hulls or the new style AA hulls.
It's the powder I started shooting with back in 1988. Soft shooting, 23 grains was the norm for a 3 dram load. It DID require wad pressure. At least 30-40 lbs. It had to be tightly compacted in that shell to avoid bloopers. Wouldn't shoot it in an auto-it burns slow, and needs a long barrel to burn right. Even at that, it will leave alot of junk (particles) in the barrel. I loved that powder-it performed great, but just make sure you have wad pressure. That's not a big deal nowadays, but with that old ball powder it was a must. I could be interested in an empty canister when you have one. It came in 10 lb cardboard canisters as I recall.
I use 473aa and it's good powder, but as all ball powder, it's hard to start. I have found most of the foreign primers have a hard time with it. I use Federal 209A primers or CCI 209M they will definitely start it.
Find the "The Complete Reloading Manual for the 12 Gauge Shotshell" It will give you all the loads with 473aa with most of the newer cases and wads. It's published by Loadbooks USA.
They sort of replaced it with WSF. 473 is a very dense ball powder. It works well in the 1-1/8 loads,but is very dirty. Ineeds a lot of wad pressure and works best with primers on the hot end. It can be used in the 20ga. also.
Has anyone had any experience using 473 in 28 ga? I too was lucky enough to be give a nice new unopened cardboard keg of 473. I have downloaded a 1980's Winchester Loading Manual for data. As others have said a good powder for 1 1/8 oz 3 dram loads and 20 gauge target loads, also, some target pistol loads in 38 9 mm and 45 ACP.
I was just wondering about 29 gauge as burn rate of 473 is close to some other good 28 ga. powders.
473AA was the go to 20 gauge skeet load for AA 20 shells. 452AA was the go to for 12 gauge AA reloads. Both had loads printed on the boxes back in the 70's when I started reloading. very good powder, I read where it could be used in both 12 and 20, but not 28. Winchester recommended 540 or 571, if my memory isn't failing, for 28 gauge. John
I went through the Lyman books and some other old manuals. None that I have list 473AA for any loads for the 28gauge. Kind of surprising, powder with burn rates on both sides of it but none for it. Sorry.