Maybe my 2008 bottle of 231 is getting old......
5.0gr with a Sutter 158 lswc bullet in my M49 only reached 816fps with a cci500 primer.

Low fps in my 9mm loads.......
oh well it is almost empty and will be used for target loads.
I did notice the "Lack" of a chemical smell when opened.

I pulled the plug with 6.8grs of HS-6.
It did 792 with a wspm but the recoil was getting to me.
For some reason a Red Dot load at 800fps did not feel quite as bad
but that was a full loading just barely into +p areas.

Universal and 2400 powder tied at 835fps but accuracy was not there, beating out
Green Dot at 822 that did have good accuracy in my snub revolver.

For some unknown reason the SR4756 load that did 890 in the 6" only put out 730fps
in the snub with a f100 primer.
Strange how things work out....... even a full boat load of Bullseye powder managed 752fps.
One reason it is easy to get frustrated in test with the little 2" barrel.
Now you will understand why I love my 6" barrels over a chrony.