Just a thought for you who shoot light or heavy for caliber bullets in your S&W revolvers. I have seen posts mentioning that the poster has gotten the best accuracy for a specific caliber when loading a standard-for-caliber weight bullet, specifically the .38 Special/158 gr. He opined that maybe This is the weight the cartridge was designed for
Without knowing it he hit on a very true fact, the 158 gr. bullet is exactly the weight the .38 Special was designed around. If you look at all the S&W calibers you will find they all have a significant similarity, sectional density and length of the standard-for-caliber bullets have, actually, two similarities that are tied together, these are sectional density and bullet
length. So what you will find by making a comparison is that bullets of the same length and profile will all have the same sectional density. They are also fired from barrels having the same rifling twist, which for center-fire revolvers is 18 3/4 inches!
So for the "standard" calibers you will see the following standard-for-caliber bullet weights:
.32 S&W Long, 100 grains +/- **
.38 Special, 158 grains
.44 Special, 246 grains
**As I recall the actual calculation was 115-120 grains for this cartridge, the same as original .32-20 factory ammunition. I don't know where my calculations chart disappeared to!
There are two exceptions, .41 Magnum and .44 Magnum. There is no "standard" cartridge for either of these, and bullet weight was determined more because the 246 grain .44 could not develop the desired velocity with the 246 grain bullet within safe pressures in S&W's and Remington's testing so they adopted the 240 grain. The .41 was sort of a hybrid having two variations with differing required velocities for different purposes.
So, because at least the .32 S&W Long, .38 Special, .357 Magnum and .44 special shoot the same
length bullets through barrels having the same rifling
twist rate, all will show very similar accuracy results. Except for the .357 they will also show very similar velocities when loaded to similar pressure levels. .357 is the exception that shows that velocity by itself is not a significant factor when it comes to accuracy!