Out of curiosity, I bought three varieties of the factory 148gr full wadcutter .38 special ammo from three suppliers to try. Today I chrono’ed them from a pair of my 2” subs.
The two guns were a S&W M12 2” and a gen 2 Colt D frame Agent 2”. Along with the chrono I shot some groups at 7 yards to see what the POI/POA relationship was and what sort of groups I could achieve with each brand of ammo.
Bottom line was the groups were all in the range of what I call acceptable for me shooting those guns DAO, the M12 always shoots tighter than the D frames, in fact it may be my most accurate revolver period.
POI was right on for windage and 1” high for the Federal Match and 1” low for the Precision One, dead on for the Choice Ammunition in the Colt, no measurable POI difference for any of the three loads for me with the M12.
Temperature was 50 deg, altitude about 800 ft. The three factory loadings were:
Federal Gold Medal Match, a lead 148gr wadcutter
Colt 646fps SD=8
M12 643fps SD=20
Precision One, a copper plated 148gr wadcutter
Colt 746fps SD=18
M12 705fps SD=13
Choice Ammunition, a copper plated 148gr wadcutter
Colt 881fps SD=18
M12 843fps SD=11
The Choice Ammunition stuff was not advertised as being +P, but certainly hotter than the rest and this is a small ammo maker who may not even have the ability to determine if it is standard pressure, I was unfamiliar with them until I got this ammo, but it was accurate and certainly stepping along.