You've got a newer P-11. The alpha-numeric serial #s began when the Office of Homeland Security had Kel-Tec begin them with a letter prefix. All the P-11 "bugs" had been long resolved before that, so you're good to go!
Just ordered a trigger shoe and a spare clip for my "A" prefix P-11. I wanted to make sure I had the 8 1/2 lb trigger and the sales person said all the "A" #s have the new spring. Wish now I had asked what other mods have been incorporated.
Yep, the P-11 had the lighter hammer springs for a couple of years before the alphanumeric numbering began, but I'm not certain where it fell in the ## range... in all likelihood you've got one of the lighter springs.
If the pull feels significantly higher than the 8 1/2 lbs, just give KT a call and have them send you out a current-manufacture spring.
Ok good my son picked up a like new p11 today with the starting numbers of 125xxx. I dont think its too old maybe a year or so but I dont know the number vs year ranges. Maybe some one out there can enlighten me.