Keith wasn't crazy. He did have decidedly strong opinions on some things and he got up on them, rode them and didn't get off. He also changed handgunning for the good.
As far as I can recall he only blew up one gun and that was a Colt SAA in 45 Colt. This was in the 1920s and the experience helped him to focus on the 44 Spl. for the reasons folks have explained.
In all his writings (Sixguns and Gun Notes in particular) he warned re-loaders to be cautious about their loading. He did not like the term "maximum loads" as used in the reloading manuals, as he believed it encouraged some re-loaders to begin at that point mistakenly thinking that those loads might be safe for their guns.
His favorite load for the 44 Spl. and later the Magnum was a 250 gr. Keith bullet at about 1200 fps from a 4" barrel. He explains this many times. In an article published in Gun Notes from March 1969 he says that the pressures were acceptable and that from a 6 1/2" barrel he got 1296 fps with the load, 1371 fps from a 7 1/2" Ruger, and 1396 from a 8 3/8" S&W M29.
There is some dispute as to whether he got that 1200 fps from a 44 Spl. gun without overdoing the pressure. He says he did with the older ballon head case but that after the 44 special brass was strengthened velocity fell off some due to less case volume.
When the 44 Spl was introduced the commercial ammo for it was loaded to the older 44 Russian loads about 700-750 fps. Shooters who had been waiting for the new round were disappointed. So they began experimenting and uploaded it.
Until the arrival of the 44 magnum Keith swore that his heavy load for the Special was the best load available from a handgun. He said this many times. The same load became his "pet load" for the 44 Magnum. (Gun Notes Vol. 1 page 132-133)
But after the Magnum arrived he laud off the Special a good deal, sometimes.
Keith kept trying to get a heavy load for the 44 Spl. introduced and marketed. But no ammo manufacturer was interested especially after the Magnum. Keith was critical of too hot 44 Magnum loads from some manufacturers. He thought that the factory loads set at 1500-1600 fps performed poorly and had frail bullets. He mentions this several times in Gun Notes.
Keith developed the 41 Magnum. When he spoke to Carl Hellstrom of S&W about it he told him that the best round for police work would be the heavy load of the 44 Spl. but that no one was interested in producing that but maybe they could sell a 41 Magnum. (Gun Notes, Vol. One page 47).
Keith left the 44 Spl. behind some for the 41 and the 44 Magnum. But the 44 Spl. remained for him a reference point round. That is he measured all handgun round performances against his heavy load for the 44 Spl.
In an article published in 1969 in Guns and Ammo on pistols he admitted he was a confirmed wheelgunner. He said...
"
When the chips are down, my own preference in handguns would be a Smith and Wesson 41 or 44 Magnum or a Ruger single action in the same calibers and my next choice is a Colt target single action in 44 Spl. caliber with my heavy loads."
The whole article can be read here...
http://www.elmerkeithshoot.org/GA/1969_07_Elmer_Keith_Part_3_Autos.pdf
http://www.elmerkeithshoot.org/GA/
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