Interesting post, and very timely as well. I have just finished reading for the 10th or so time a write up in Guns and Ammo dated Jan 1969 titled "Loads for Handguns" by the man himself. I have recenetly gotten into casting my own and in doing research for molds and loads I have read some VERY intersting history on both from the original developers.
In this particular article Mr. Keith speaks about his favorite loads in various calibers and being at the Remington, and at the Smith and Wesson plant in 1953 working on the 44 Mag. It also mentions the fact that Remington was afraid of his heavy 44 Spl load of 18.5gr of 2400 due to the "Triple Lock" strength and that is when they lengthened it by 1/10".
As has been mentioned here, his most preferred load was with 22grs of 2400 under his Ideal 429421 250gr hardcast. I have been there with a similar load, and agree it is one that gets my full respect of the caliber and what it can do. I have also run H-110 up to levels I felt were easily more than enough, back before it was changed over to the same powder as 296. I still have one partial bottle of that sitting on my shelf and it is NOT even directly interchable with 296 data.
I have through the years fired but few factory rounds through my 44, but of the ones that I have run through it that got my attention the most were the 180 and 240gr loads from PMC, back in the early 90's. Either of them would easily top my handloads out of my 7.5" Redhawk. In the past 10 years or so I haven't even been bothered with factory in anything except my 454, and the initial two boxes I had were the Winchester medium loads, and were presented to me with the revolver as a gift. As such I really haven't got a clue as to what or how they are loaded these days. I guess i gave up on factory loads completly, when they, like Nosler, decided that it was better to put half the rounds in a box but charge you as much, or more in some cases, as what they had been for a full box. I haven't shot them myself, but from what I read and hear the Buffalo Bore rounds will get ya a full power load in just about anything they put out. But there again you pay for that premium.
I have used 23.5grs of 296 under the Remington 240gr SJHP fo so long I think my Uniflow simply dials it's self in when I set the box of bullets and tray of brass on the bench. While I do admit to pushing it a bit harder in my earlier days, I sat down at the range one day and worked the loads up in small increments until I could put no more powder in the case, and still seat the bullets to the cannelure. With all else remaining the same, the 23.5 loads I had been shooting, with this particular lot of powder, was not only the most accurate but produced single digit ES. For me that was plenty good as it was shooting 1" groups at 100 with the 4x Leupold on top.
I agree that there have been major reductions in plenty of loads and data over the past decade for sure. Some call it lawyer work some call it better testing equipment and proceedures. Me I just keep plodding along looking for accuracy first, then velocity. When they both come together in one load, well thats just he iceing on the cake.