I've chrono'd that Federal 115 gr FMJ, 9mm ammunition through a Glock 19 and got 1085 fps for an average of 5 shots. By contrast, Remington Golden Saber 124 JHPs went 1151 fps for 3 shots; while Winchester White Box 115 JHPs went 1041 fps. If any are under powered, they aren't by very much and function well in all my 9's. (Sig P290, Colt Combat Commander, Colt Gov't Model with 5" barrel, Beretta 92, and Glock 19)
I'd recheck your extractor hook, recoil spring and mainspring for wear or damage, also the chamber condition...i.e. nicks or rough machining marks.
Best regards, Rod
Our Flag does not fly because the wind blows against it,
It proudly waves because a soldier's dying breath blows upon it.
USAF Forward Air Controller, 5th Spl Forces,
An Loc, lll Corps, RVN, 69-70, Vietnam Vet '69-'73