Yes the barrels work fine... just wanted the extra length and maybe a little help with muzzle rise on the .40. If they made one for the P45, I would get one so they would all be alike. I had an SS K9 from March 1998 and finally sold it as I carried nothing but polymers. The P9 is 8 ounces lighter than the K9 and the P40 only a bit more.
Below, the 4" ported barrel for the P9 or CW9, K9(I think), P9, and PM9. The ported barrel seemed to fit in the K9, but I wouldn't fire test it. I only have the P9 now.
I did have a Mag-na-ported SS P40(bought used), but I got a chance to get a new black one and sold the SS one. I only have the minimum 4 Kahrs now, and the P9 really is just a backup.
USAF Retired '88, NRA Life Member. Wife USAF Retired '96
Avatar: Wynn re-enlists his wife Desiree, circa 1988 Loring AFB, ME. 42nd BMW, Heavy (SAC) B-52G's
Frédéric Bastiat’s essay, The Law: http://mises.org/books/thelaw.pdf
Thomas Jefferson said
“A government big enough to give you everything you want, is strong enough to take everything you have.”
and
"Peace is that brief glorious moment in history when everybody stands around reloading".