My purpose in performing this experiment was to demonstrate that reverse-loaded SWC bullets perform satisfactorily. And so they do. Grouping is equivalent to the DEWC bullets I normally use, and there is no sign of instability at 25 yards as evidenced by lack of any indication of yaw (keyholing). Regarding the "sharpness" of the holes produced on a paper target by full wadcutters vs. semi-wadcutters, there is a discernible difference - the flat nose is better in that regard, even though the SWC is not bad.
I put this information forward mainly as a matter of information should anyone else wish to duplicate my test. For PD use, the heavier SWC bullet loaded backwards might have a bit of performance edge over a conventional full wadcutter or a SWC loaded normally. At one time, there was a factory "Full Weight" wadcutter load with a 158 grain bullet, and by reversing a SWC, performance would be duplicated.
DWalt,
I understand what you are getting at, just not why.
The .38 Mid-Range (25 Yd) Wadcutter at a reduced bullet weight was developed many years ago as a very specialized cartridge for a specific purpose.
Yes, there were 158 gr. full-load wadcutter cartridges at one time, and they fell out of use, and production, because there were better choices for 50 yd. target work. If you want to experiment with this sort f load, Lyman had a bullet, the 358432, which was a full weight wadcutter. It was available in either 148 or 160 gr versions. My 4 cavity throws 158 gr. with #2 metal. This is the bullet Skip Sackett has shown photos of.
The reason for the demise of the full power wadcutter was because of a loss of accuracy with this style bullet at ranges much beyond 25 yds. This is because the wadcutter has a poorer form stability factor than a SWC or RN bullet. Not necessarily enough to cause tumbling at 50 yds, but enough to cause group size to increase enough to reduce average scores. Where 1 X score could win or lose a match this was important.
Form Stability is why solid base wadcutters usually have a button nose, it improves form stability over a straight cylindrical wadcutter like the HBWC bullets usually are. Your reversed semi-wadcutters will have an even poorer form stability factor than a normal wadcutter, and accuracy will degrade over range even quicker. Again, they may not tumble at reasonable ranges, but they will not shoot as well as when loaded normally. You may need a machine rest to see the difference at ranges under 50 yds, but it will be there.
So far as cleanness of the holes cut in a paper target are concerned, if you think you can tell the difference between a full wadcutter and a semi-wadcutter you are kidding yourself.
Best I could do on short notice! 
