I did some recent testing with some shotshells that I just reloaded, and also some factory CCI 38 spcl. shotshells.
I shot them from my Ruger SP101 2-1/4" barrel.
I used 38 spcl. cases
5.0 grains of HP38
90 grains of #7-1/2 shot (from a shotgun shell)
The CCI shotshell uses #9 shot, as I recall.
Here is a couple of pictures showing the difference between the two:
On the left is the CCI Shotshell. On the right is my "home made" shotshell result.
Click on a picture and it should expand to a bigger picture.
There is a definite difference in the two shot sizes.
The #7-1/2 shot gave a tighter group. Perhaps because of the heavier shot.
Anyway, I am happy with these and thought you folks would be interested.