Here are the results of a test done by Grennell and Clapp some years back for a Gun Digest publication.
The gun was a FACTORY ORIGINAL (not modified in any way) 92FS.
Shooting off the bench with a V-Rest @ 25 yards--I think these are 5 round groups--it doesn't say.
Winchester Silver Tips 2.75"
Federal 9BP (115 JHP) 2.5"
Federal 9AP (124 JHP) 3.5"
Shooting from a Ransom Rest @ 25 yards. These are 20 (TWENTY) round groups.
I'm going to list the 5 best
Federal 9BP 2.31"
Geco 123 FMJ 2.67"
Fiocchi 115 FMJ 2.76"
Norma 115 JHP 2.77"
Rio (??) 115 JHP 3.04"
This was published about 10 years ago, some of the ammo listed doesn't seem to be available anymore.
Anyway, the top 4 ammo types stayed under 3"
The top 14 types stayed under 4"
Remember, these are 20 round groups, not the normal 5 or 10.
Later, they took the gun used in this testing and had a Bar-Sto barrel fitted.
The fitted barrel cut TEN shot group sizes by about 1" at 25 yards from the Ransom Rest.
Here are the 10 shot groups fired with the fitted barrel
Federal 9BP 1.23"
Winchester STHP 2.03"
Federal 9AP 2.11"