act the risk of sounding persnickety, Ol' Joe,
Your analysis of 'conflicting' reload data is excellent--but does nothing to solve the problem. I'm dealing with this problem myself right now--I want to develop good reloads for use in a J-frame with a nominal 2" barrel.
(Background: the VT incident convinced me to get going with CC again--and this time I decided to carry the proverbial snubby revolver. I want to get VERY proficient in its use, so I want some reloads for practice. I actually bought two--the S&W 340 for carry, and the 640 for practice / alternate carry.)
I have found a real lack of data resources for 2" barrels, and I need to make some 'reasonable' extrapolations.' The real trick, of course, is what's 'reasonable?'
Here's a couple of related issues, besides the barrel (length) issue--nominally-similar bullets. I found a lead 105-TC to load, and bought that--still looking for a lead 110-gr. Hopefully, this bullet would allow me to replicate my chosen FC 110 gr SD load--at least so I can practice with the alloy frame gun to get proficient with it.
I think some 'reasonable' assumptions are the following:
1. 'Similar' bullets have similar loading characteristics Loads (specifically, for 231) and specs for a 110 gr. bullet in general (Lead or JHP) are considered similar, and a variable at least in the mid-load range. A corrolary here is that given a bullet weight, charges will vary by bullet type--e.g., lead and jacketed.
2. Powder, and to a lesser extent primer (brand and type) is specific and not 'exchangable,' and is a constant.
3. LOA is a another constant, selected for minimum alteration during initial development.
4. Standardized development techniques are mandatory.
5. Stay in the moderate range of loads; avoid minimum or maximum loads.
In general, then, it seems to me that a careful analysis based on set theory ought to help us a lot. Further, 'top-down' organization (old computer programming principles) are helpful in organizing our constants and variables.
For example, on the barrel-length issue here: Given any readily-available powder, is reasonable to assume that velocities from a 2" barrel will be less than from a 6" barrel--particularly for 'older' cartridges' data.
I am constantly Googling this stuff--and just last night, while rumbling around the new Hodgson data base, I discovered there appears to be several .38+P pressure-level loads with 231 and 110 gr bullets
in the .357 magnum recipes. As a result, I ordered out some .357 brass and SPM primers.
Finally, nothing beats experience, and lots of it. A careful, MINIMAL manipulation of variables is one way to grow. And all bets are off if you are working with, for example, Winchester 296 powder.
If anyone else can join in here to help refine these principles, I'd appreciate it.
Jim H.