Do you happen to have any catalogs or literature showing that?
I've heard the same before but have never seen it documented. Also, which bullet weight are you talking about?
Jose, I have "The Complete Guide To Hand loading", Third Edition, Second revision, authored by the renowned Philip B. Sharpe, first published in 1937, and my copy published in 1953. Google Philip Sharpe if you don't know the name offhand. As a contemporary of Harry M. Pope, who Sharpe called "The Old Master", and Elmer Keith, Sharpe has the Bone Fides to back up his publications.
Sharpe lists maybe 200 loads for the .38 S&W Special. They range from 73 grain bullets, up to 200 grain bullets. They include loads with common powders of the time including Bullseye, Unique (Still my two favorite powders), SR80, Her. Red Dot, and a 200 grain bullet load using "Infallible" powder, recommended by Maj Julian Hatcher.
Let me make this short by saying there are loads that range from 1400 fps, to as low as 480 fps for a Hercules load of a 200 grain bullet.
If I just stick with loads for 146 grain bullets, to the 160 grain Keith bullet, there are
MANY loads that exceed 1285 fps with Unique with a 146 grain bullet with a breech pressure of 28,000 pounds, all the way up to 1150 fps with a 158 grain bullet behind 11 grains of SR80 powder good for 38,000 pounds of breech pressure, as recommended by DuPont.
The fastest load I see is 1511 fps for a 146 grain bullet using 16 grains of Herc 2400 with a breech pressure of 35,000 pounds.
These loads are all from a 6 inch barrel, and include a few that state the velocity is achieved with corrosive primers. I don't know if more modern non-corrosive primers would produce more or less velocity vs pressure.
One of my favorite loads is a 158 grain bullet at 1130 fps using 6.6 grains of Uniques, with a breech pressure of a mild 20,900 pounds.
If you can find a copy of Sharpe's manual, I think you'd freak out. His handgun loading table include .25, .32 S&W, .357 S&W Magnum, .44 S&W, and a ton of other loads, too numerous to mention.
You might find a copy at ABLE BOOKS or some of the other Firearms related specialty book shops on line.
I got my copy when the Wrentham, MA public library sold off excess/ obsolete books in 1980. It's remarkable that there is a sticker in the cover of the book that says: "Purchased by the Fiske Public Library, 1965 through State Aid to Public Libraries." It was put on the shelves in Wrentham in 1966.
I'm sure there are other manuals out there, but Philip Sharpe was THE MAN in those days.
Bill