If this helps.....
The book that came with the gun said "not to use +p ammo" and when I spoke with Springfield they said it was due to the slide cycle rate, the new ones are suppossed to have a dual spring set up mine did not. The web site did not list this and when I asked Springfield about the gun before buying it they failed to mention it. They said they would look into putting it on the site, I see they did not.
Mine feed FP and JHP's fine, just didn't like +p wish they would have told me before I spent $742 on the gun. Gun owners are not very forgiving. I will not buy another just because of the way they handled my deal on the phone.
Jim does your gun have the single or dual spring set up and does it say in the manual not to use +p ammo.