Boats,

I like to use that method too.
Have a lot of the old Ideal/Lyman manuals with few gaps, and the bullet and powder suppliers manuals, plus additional references.
Like to start a cartridge sheet like you posted, and then list data from the different sources chronologically - which makes errors in a particular reference release stand out real fast, so I can then make a precautionary highlight on the sheet.
Also interesting to tract how some old standard powders (still in production) for particular cartridges and loadings gained and lost favor over time to newer introductions through the years.
32-20 is also an interesting cartridge to follow, having been available in both rifles and revolvers, and seeing the load data diverge and follow different paths as Hi-Vel loads were introduced for rifles, while the 32-20 revolver loads start to disappear as that chambering in revolvers, and then some of the revolver models themselves were phased out.

Thanks for the sizing

Sometimes I wonder when a recommended load repeats, could it be one author saw it and inserted the data into his manual ?  That 6.5 4227 6.5 SR # 75 load at about 1350 FPS is mentioned in several places including two Internet forums 

Although it seems to be the one I will end up with. Won't know for sure until I get a tang sight on the gun. Open barrel sight it's just a guess how it's shooting. My guess is it's pretty good. Will see.

Boats

Marlene, those "equivilant" quips are more about being suitable for something, not exactly measure for measure. While giving a clue about what calibers it may be good in, you still need to exercise caution when interpolating the data for any powder. And, that doesn't even account for the changes from then till now. Just be careful, please.

Way back before the Internet, Ken Walters of Handloader magazine would answer questions by letter for a small fee. 5 dollars I think. He sent me a nice reply about SR # 80 "equlivent to" 4759.  Included the appropriate cautions about starting low and working up. 

My 25/20 work about 1300 fps is considerably under the High Speed loading for the catrtridge.  Still caution is good and few  tested so far started well under the old manuals data.

Have to look for that letter & post a copy.

Boats

Well said !   For exciting loads look at Ackleys manuals, it's a wonder some of those rifles stayed together.

Boars

Vall, when I first started shooting cast bullets I bought an old copy of the Lyman Cast Bullet Handbook and a new can of Reloder7. i worked up a load based on accuracy and kept charges within a grain of max.  I later bought a chronograph and I found I was getting max velocity on the lowest powder charge!

I wrote Alliant and was told that my velocities were what they would expect given the powder charge and bullet weight.

Chris.

40 Rod, you point out something that is worth discussion. ALL powders, sooner or later will be replaced by something else. Replaced isn't what we think of when we change a stock screw for another one when we bugger it up. The replacement is more often in the vein of "improvement" in some corporate views. Profit is likely to be among the so-called improvements. Lately, 4759 has been removed from the list of available powders. The supposed successors aren't at all the same in actual use. The new  powders of earlier time weren't all well received by users. Ned Roberts bemoans the loss of some of the old ones. Others did the same. And, the wheel goes around one more time.