Winchester 231 in 45ACP

Hi Guys
I had decided to use 231 instead of Unique, mostly because of the smoke in indoor shooting. I got out the "One Book/One Caliber" but the data looked strange,so I made a plot of powder weight vs velocity and it looks like two different powders. For example; Hornaday max is 6.5 gr but Winchester max is 5.5gr. for about the same velocity. I dug up some really old data, Ken Waters Pet Loads/ Handloader Magazine (1978) where he tried 5.0 and 6.0 gr and reported that 5.0 gr would not function reliably in his test gun. I tried a load listed on the Hodgdon Website of 4.4 gr and it functioned fine in my 1911's. That makes me think that there really are two set of loading data, one for an "old" powder and one for a "new" powder. Maybe Hodgdon changed the powder formulation when they took over making 231.

The data from the current Hodgdon Website should be the newest (4.4 gr/771 fps and 5.6 gr/914 fps). But the Third Edition of the Lyman P&R Handbook (2004) still has what I think is "old" data.

This is all data for 200 gr LSWC. What do you guys think ?

Published results reflect only what was observed with the specific components and specific test firearm that was used to generate it. Every bullet, barrel, case lot, and batch of propellant are different. It would be very odd indeed if they were all in agreement.

Old data can be dangerous for several reasons, the two most important are that powders do change and the methods of determining pressure have changed also. Even data five years old can be dangerously out of date for certain powders.

I think every loader should have a minimum of three current manuals and when contemplating a load should consult all of them. Not only are the testing circumstances and components different, humans can make errors and some of them work in data entry. It is not unusual to find incorrect data in manuals - it doesn't happen often, but still often enough so that I would never rely on just one source, especially if the powder was new to me. And if you have two sources and they disagree, it's nice to have a third and a fourth to double check. Then too, not all manuals will list all available powders and bullet weights, so the more different manuals you have, the more likely it is that all your bases are covered. Think of them as the least expensive life insurance you can buy.

also the components used make a huge difference.
some cases have a tad less capacity,and some bullets have more bearing surface.
also with the 45's there is a huge difference in chamber tolerences. and the primer brisance in such a small area will affect the pressure too.
hence the adage of start low and work up.
ken waters loads seem pretty sensible if you see what he did there.