Will a PF9 barrel fit and work in a P11. The look exactly the same except for the feed ramps. The PF9 ramp is maybe a 1/4 inch longer, and therefore a straighter shot for the bullet nose. From pictures it seems that the original PF9s had the same profile barrel as the P11, but after feeding problems discovered early on, they changed to the longer feed ramp barrel. My p11s feed fine on live fire, BUT, sometimes in hand chambering, they hang up on Speer 124 grain hollow points. Anybody own both, and want to swap barrels in your two guns as a little experiment?