Interesting. All I could find was these links, all of which showed lower velocities, although the factory links stated a 4" vented test barrel was used.
Is this what you bought? Note the lower velocity listed.
[url=http://www.luckygunner.com/38-special-125-gr-sjhp-remington-umc-100-round#info]
Remington
Handgun | Remington
This link is interesting simply because it lists a snub barrel length, although it's for the UD line, not the bulk/UMC.
Remington